ControlChips CY545 User manual

CY545
High Performance
Stepper System Controller

CY545 Stepper System Controller
www.ControlChips.com
© 2002 Cybernetic Micro Systems Table of Contentsi
Copyright and Disclaimer Notice
Cybernetic Micro Systems, Inc. software products are copyrighted by and shall remain the
property of Cybernetic Micro Systems, Inc. Duplication is subject to a license from Cybernetics.
Cybernetic Micro Systems, Inc. reserves the right to improve design or performance
characteristics. Cybernetic Micro Systems, Inc. assumes no responsibility for the use of any
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are implied.
Information furnished by Cybernetic Micro Systems, Inc. is believed to be accurate and reliable.
However, no responsibility is assumed by Cybernetic Micro Systems, Inc. for its use, nor for any
infringements of patents or other rights of third parties which may result from its use. No license
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Systems, Inc. Further, Cybernetic Micro Systems, Inc. reserves the right to revise this
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notify any person or organization of such revision or changes; and Cybernetics assumes no
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Because of the wide variety of applications in which this product may be used, Cybernetic Micro
Systems makes no claim as to the product’s fitness for any given application. It is therefore the
user’s responsibility to ensure the safety and viability of using this product in his application.
This product is not recommended for use in critical life sustaining applications.
The following are trademarks of Cybernetic Micro Systems, Inc:
Bin-ASCII CY250 CY512
CYMPL CY300 CY525
Analog-ASCII CY325 CY545
ASCII-Analog CY327 CY550
CY123 CY360 CY600
CY132 CY480 CY750
CY232 CY233-LINC P-51
CY233 CY500 USB-RAM
All rights reserved; no part of this publication may be reproduced, except for personal and
archival uses, without the prior written permission of:
Cybernetic Micro Systems, Inc.
P.O. Box 3000, San Gregorio, California 94074 USA.
Tel: [phone] • Fax: [phone]
www.ControlChips.com • [email protected]
01/28/02

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© 2002 Cybernetic Micro Systems Table of Contentsii
Table of Contents
Table of Contents..................................................................................................................... ii
Table of Contents....................................................................................................................ii
Chapter 1 - Introduction to the CY545 .................................................................................... 1
CY545 Stepper System Controller...................................................................................... 1
Basic Features ............................................................................................................... 1
Motion Control Functions................................................................................................ 2
Motor Support Signals .................................................................................................... 2
General Command Functions and Special Features....................................................... 3
Prototyping Board Support ................................................................................................. 3
CY545 Stepper Motor System Controller............................................................................ 4
Chapter 2 - Pinout & Package Overview................................................................................. 5
CY545 Dip Pinout & Dimensions ........................................................................................ 5
CY545/J PLCC Pinout & Dimensions ................................................................................. 6
CY545 DIP & CY545/J PLCC Pin Descriptions .................................................................. 7
Chapter 3 - Command Interfaces ...........................................................................................11
Command Interfaces .........................................................................................................11
Parallel Interface ...............................................................................................................11
CY545 Interface to CY233 Network Control Chip ..............................................................11
The CY545 Serial Interface ...............................................................................................12
Chapter 4 - Command Summary............................................................................................15
CY545 Command Summary..............................................................................................15
Command Formats............................................................................................................16
ASCII Command Format ...................................................................................................16
Binary Command Format ..................................................................................................17
Chapter 5 - Motor Control Commands...................................................................................18
Motor Control Commands .................................................................................................18
Set Stepping Rate .............................................................................................................18
Set Count and Direction ....................................................................................................18
Set Step Mode ..................................................................................................................19
Moving the Motor ..............................................................................................................20
Position Counter “Wrap-around”........................................................................................20
Chapter 6 - Bit Function Commands .....................................................................................21
Bit Function Commands ....................................................................................................21
User Bits ...........................................................................................................................21
Bit Dependent Jump and Wait...........................................................................................22
Step/Test/Seek Home Command ......................................................................................24
Special Note Regarding Older Versions ........................................................................24
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CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Table of Contentsiii
Chapter 7 - External Memory Commands .............................................................................25
External Memory Support Commands...............................................................................25
External Memory Address Pointer .....................................................................................25
Writing Commands into Memory .......................................................................................25
Running From External Memory........................................................................................26
Example ............................................................................................................................28
Chapter 8 - Program Branch Commands ..............................................................................29
Jump and Loop .................................................................................................................29
Nested Loops ................................................................................................................29
Chapter 9 - Operating Mode Command.................................................................................31
Operating Mode Command ...............................................................................................31
Chapter 10 - Miscellaneous Commands................................................................................35
Initialize Command............................................................................................................35
Time Delay Command.......................................................................................................35
Query Command...............................................................................................................36
Display CY545 Status....................................................................................................36
Display Memory Contents..............................................................................................37
Message Display Command..............................................................................................38
Embedded Control Characteristics and Their Use: ........................................................38
Hewlett Packard (HP) LED 8 Digit Display.........................................................................38
LED Display Details.......................................................................................................39
Chapter 11 - CY545 Example Circuits....................................................................................40
Three Example Cases.......................................................................................................40
CY545 Example Circuit – Minimum Serial Configuration ...............................................40
CY545 Example Circuit – Minimum Parallel Configuration.............................................41
CY545 Example Circuit – Maximum Configuration ........................................................42
Chapter 12 - External Memory Support .................................................................................43
Memory Read/Write ..........................................................................................................43
“Auto-Start” Feature for Stand Alone Operation.................................................................44
Chapter 13 - Thumbwheel Switch Support............................................................................46
Thumbwheel Switch Support.............................................................................................46
CY545 Thumbwheel Switch Parameter Addresses ..........................................................49
CY545 Thumbwheel Circuit Diagram ................................................................................50
Chapter 14 - CY545 Output Display Support.........................................................................51
Output Format ...................................................................................................................51
Output to LCD (CY325-Based)..........................................................................................51
Output to Parallel Device (Including CY233 Network Chip) ..............................................52
Output to 8-Digit LED Display............................................................................................52
Chapter 15 - CY545 Prototyping Support ..............................................................................54
The CYB-545 Prototyping Board .......................................................................................54
CYS-545 Panel Software...................................................................................................55
CyberCom Console Software ............................................................................................55
The CYB-233 Prototyping Board .......................................................................................56
The CYB-003 Prototyping Board .......................................................................................57

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© 2002 Cybernetic Micro Systems Table of Contentsiv
Chapter 16 - Timing and Control............................................................................................58
Timing and Control............................................................................................................58
The Parallel Handshake ....................................................................................................58
Immediate Commands During External Memory Program Execution ...........................59
The Serial Interface...........................................................................................................62
External Memory Control Signals ......................................................................................63
Special HP LED Display Control Signals ...........................................................................65
Thumbwheel Switch Interface Control Signals...................................................................66
Stepper Motor Interface Signals ........................................................................................67
PULSE and CWW .........................................................................................................67
STOPPED .....................................................................................................................69
SLEW ............................................................................................................................69
INHIBIT_ABORT ...........................................................................................................70
CW_LIMIT and CCW_LIMIT..........................................................................................71
JOG Mode Operation ....................................................................................................72
Automatic Position Display ................................................................................................73
Home Signal..................................................................................................................73
Chapter 17 - CY545 Step Rate Information............................................................................75
CY545 Step Rate Information............................................................................................75
The Slope Parameter ........................................................................................................75
Optimal Acceleration Curves .............................................................................................76
Acceleration Curve as a Function of R ..............................................................................76
Slope and Elapsed Time ...................................................................................................77
CY545 Slope Curves.........................................................................................................78
CY545 Step Rate Table @ 11 MHz...................................................................................81
CY545 Step Rate Table @ 12 MHz...................................................................................82
CY545 Step Rate Table @ 14.75 MHz..............................................................................83
CY545 Step Rate Table @ 16 MHz...................................................................................84
Chapter 18 - Electrical Specifications ...................................................................................85
CY545B Electrical Specifications.......................................................................................85
Electrical Conventions.......................................................................................................85
Reset Circuitry...................................................................................................................85
Clock Circuits ....................................................................................................................86
Chapter 19 - Circuits and Examples ......................................................................................87
Variable Stock Cut and Punch...........................................................................................87
Driver Circuit Considerations.............................................................................................89
Interfacing to the 8255.......................................................................................................92
Operating Several CY545s Using a Common Data Bus ....................................................93
Synchronization of Two CY545s........................................................................................93
Coordination of Several CY545s .......................................................................................94
Example Programs and Waveforms ..................................................................................95
ASCII and Binary Data Programming Examples................................................................96
Chapter 20 - Getting Your CY545 Running............................................................................97
Getting Your CY545 Running ............................................................................................97
BASIC Language CRT Emulation Program .......................................................................99
Changes from CY545 to CY545A....................................................................................101
Changes from CY545A to CY545B .................................................................................101
Stepper Motor Controller Selection Guide .......................................................................102

CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Chapter 1 - Introduction to the CY5451
CY545 Stepper System Controller
In 1979 Cybernetic Micro Systems invented the first Single Chip Stepper Motor Controller, the
CY500. Since then we have continued to design improved versions, the CY512 (1981), the
CY525 (1983). This manual introduces our (1988) fourth generation device, the CY545
Stepper System Controller. A fifth generation device (1993) the CY550 is also available. The
CY545 is the first Stepper Motor System Controller chip, to offer completely new features,
such as:
•27,000 Steps/Sec
•Million step motions
•Serial or Parallel interface
•LED display interface
•LCD display interface
•Thumbwheel switch interface
We believe this device offers all of the features you want to implement sophisticated motion
control systems at very low cost.
For example, our CY500, CY512 and CY525 controllers work best in systems with a host
computer that issues single commands, or sequences of commands as a program, to the
controller, and then tends to other system functions while the Stepper Motor Controller is
running the motor. Maximum performance is gained when the host CPU is closely coupled to
the Stepper Motor Controller IC.
While the CY545 is also capable of working with a host CPU in a closely coupled fashion, the
CY545 contains extensions that allow it to function very well in a stand-alone system. In fact, it
is possible to base a simple controller design around the CY545, and operate a machine with no
CPU at all, bringing the benefits of intelligent, programmable stepper motor control to
applications that do not justify a host computer system.
Basic Features
•Single 40 pin 5 volt CMOS integrated circuit
•Simple ASCII letter based commands and parameters
•Simple application for basic stepper motor functions
•Operation with a host computer or stand alone
•Built-in Display interfaces for alpha-numeric LED or LCD
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CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Chapter 1 - Introduction to the CY5452
Motion Control Functions
•Programmable step rates from 20 steps/sec to over 27,000 steps/sec provide extremely
large dynamic range.
•Linear acceleration curves for optimum performance.
•Partial accelerations make short moves in the least time.
•Separate parameters for starting rate, final rate, and acceleration values allow totally
programmable motions.
•Relative moves of +/- 16 Mega steps from current position. Absolute moves within a 16
Mega step range.
•Continuous moves with no specific number of steps, allow acceleration from the starting
rate to the final rate, followed by an indefinite run length.
•Internal step position updated during all motions.
Motor Support Signals
•Step Pulse and Direction signals
work with standard power driver
modules.
•Internal or external direction
control.
•Forced ramp down and abort
signal for emergency or externally
controlled end of motion.
•Separate CW and CCW limit
signals inhibit stepping beyond
one limit, but allow stepping in the
opposite direction.
•Moving/not moving signal for use
as Motion Complete or to switch
stepper power driver between
high and park power.
•Externally operated jog mode,
with direction control and
start/stop control from one signal,
all at programmable manual
control step rates between 1 and
1K steps/sec.
•Automatic home sensor seek,
with backlash compensation.

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© 2002 Cybernetic Micro Systems Chapter 1 - Introduction to the CY5453
General Command Functions and Special Features
•Parallel command interface with two line handshake, compatible with CY233 network
communications controller.
•Serial command interface with fixed or adaptive baud rate selection.
•Support for up to 64K of optional external command memory implemented as RAM,
ROM, EPROM, or EEPROM.
•Support for optional external setting of parameter values, through standard thumbwheel
switches.
•Selectable display for output messages from standard serial, standard parallel, or CY233
interfaces, plus special support for a parallel HP HDSP-211x LED display, or a CY325
based serial LCD display.
•User controlled, multi-purpose I/O lines, for:
•set and clear bit functions
•test bit and branch functions
•wait for bit value functions
•automatic home seek functions
Prototyping Board Support
The CYB-545 Prototyping board implements most of the available features of the CY545
Stepper System Controller. A more complete description may be found in the chapter on
Prototyping Support.

CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Chapter 1 - Introduction to the CY5454
CY545 Stepper Motor System Controller

CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Chapter 2 - Pinout & Package Overview5
CY545 Dip Pinout & Dimensions
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CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Chapter 2 - Pinout & Package Overview6
CY545/J PLCC Pinout & Dimensions

CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Chapter 2 - Pinout & Package Overview7
CY545 DIP & CY545/J PLCC Pin Descriptions
DIP PLCC Pin Name Description
-1(O)NC No connection
12(O)PULSE/ Step pulse output, one pulse per step
2 3 (I/O) CCW Step direction
These pins run the stepper power driver. A high level on the direction
signal indicates counter clockwise direction, while a low level indicates
clockwise direction. The Pulse signal is normally high, going low at the
beginning of each step.
DIP PLCC Pin Name Description
34(O)STOPPED Motion status, low while stepping
This signal may be used to indicate motion complete, by its high level. It
may also control power selection for the stepper driver, switching
between high power for stepping, and parking power while stopped.
DIP PLCC Pin Name Description
45(I)CW_LIMIT/ Clockwise step limit reached
56(I)CCW_LIMIT/ Counter Clockwise step limit reached
If either signal is low, it indicates a limit has been reached. The CY545
will not continue stepping in that direction until the limit signal is removed.
Normal stepping is allowed in the opposite direction.
DIP PLCC Pin Name Description
6 7 (I/O) JOG Manual stepping control
This signal is the manual stepping control input. When it is floating, the
CY545 will not jog. However, if the signal is connected to ground, the
CY545 will jog in the CW direction. The jog step rate is derived from the
First Rate parameter and the normal Step Rate Table, by dividing the
selected rate by 20. This gives a range of about 1 step per second to
about 1000 steps per second. The input signal is always enabled, and is
tested by the CY545 while it is not executing another command.
DIP PLCC Pin Name Description
7 8 (I/O) SLEW/ Slew indicator signal
89(I)INHIBIT_ABORT/ External motion control
This signal group indicates and controls motion status. SLEW/ indicates
when the maximum selected step rate has been achieved. If externally
driven low at the beginning of a motion, it also selects the continuous step
mode. INHIBIT_ABORT/ can hold off motion at the start or force an early
down ramp, then stop motion when the CY545 has ramped down to the
starting rate.

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© 2002 Cybernetic Micro Systems Chapter 2 - Pinout & Package Overview8
DIP PLCC Pin Name Description
910(I)RESET CY545 hardware reset, active high pulse
10 11 (I) RxD Received serial data into CY545
-12(O)NC No connection
11 13 (O) TxD Transmitted serial data from CY545
These are TTL level serial data signals that can be used to issue
commands to or get replies from the CY545. Addition of an RS-232
voltage level driver/receiver, such as the Maxim MAX233, allows any RS-
232 device, such as the IBM PC COM1 port to talk directly to the CY545.
DIP PLCC Pin Name Description
12 14 (O) SW_SEL/ Switch select
This signal is active when the CY545 is reading a parameter value from
external thumbwheel switches. The switch address is generated by the
parallel data bus.
DIP PLCC Pin Name Description
13 15 (I) IO_REQUEST/ Parallel handshake input signal
This signal is driven low when a parallel command is issued to the
CY545. It is used as part of the parallel command handshake. If the
parallel command function is not used, this signal may select a fixed
serial baud rate as follows:
0 = 300 baud, 1 = 2400 baud, F = 9600 baud
DIP PLCC Pin Name Description
14 16 (I/O) XMEM_SEL/ External local memory select
This signal goes low when the CY545 reads or writes to the local external
memory. Data and addresses are generated by the parallel data bus. Up
to 64K bytes of external memory are supported. When this signal is
driven low at power-up or reset, the CY545 will not test for the Auto Start
key sequence or automatically execute commands from the external
memory.
DIP PLCC Pin Name Description
15 17 (I/O) BUSY/ Parallel handshake acknowledgement
BUSY/ is used with IO_REQUEST/ to implement the two line parallel
command handshake. This signal indicates that the CY545 has accepted
a parallel data character from the device driving the IO_REQUEST signal.
If the parallel handshake is not used, this pin may be tied low to select
fixed baud rates through the IO_REQUEST signal.

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© 2002 Cybernetic Micro Systems Chapter 2 - Pinout & Package Overview9
DIP PLCC Pin Name Description
16 18 (O) WR/ Write strobe
17 19 (O) RD/ Read strobe
These strobes are active while the CY545 is reading from the external
thumbwheel switches, display, or memory, or while it is writing to the
external display or memory.
DIP PLCC Pin Name Description
18 20 (I) XTAL2 Crystal connection
19 21 (I) XTAL1 Crystal connection
An external crystal or clock source is connected to these pins, with a
value between 3.5 MHz and 16 MHz. For serial communications, an 11
MHz crystal will give standard baud rates.
DIP PLCC Pin Name Description
20 22 (I) VSS Power supply ground.
-23(O)NC No connection
DIP PLCC Pin Name Description
21 24 (I/O) USRB0 User selectable function, bit 0
22 25 (I/O) USRB1 User selectable function, bit 1
23 26 (I/O) USRB2 User selectable function, bit 2
24 27 (I/O) USRB3 User selectable function, bit 3
25 28 (I/O) USRB4 User selectable function, bit 4
26 29 (I/O) USRB5 User selectable function, bit 5
27 30 (I/O) USRB6 User selectable function, bit 6 or FPL/ or CTS/
28 31 (I/O) USRB7 User selectable function, bit 7 or HP_SEL/
This group of signals is used for multiple, user selectable functions,
including bit set and clear, bit test and branch, wait for signal value, and
auto home functions. Any function may be performed on any bit. Bits 6
and 7 also have fixed alternative functions of CY233 FPL control and
local parallel HP display selection if these features are used with the
CY545. If the application does not use a CY233, CTS/, or HP display,
these bits may be used for any other functions.
DIP PLCC Pin Name Description
29 32 (O) RESERVED Reserved signal, not used by CY545
30 33 (O) ALE Address latch enable
The ALE signal is used to demultiplex the lower byte address from the
data bus during external memory, display, or thumbwheel switch
operations.
DIP PLCC Pin Name Description
-34(O)NC No connection
31 35 (I) TEST Internal test signal, connect to Vcc.

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© 2002 Cybernetic Micro Systems Chapter 2 - Pinout & Package Overview10
DIP PLCC Pin Name Description
32 36 (I/O) D7 Parallel data bus, bit 7, MSB
33 37 (I/O) D6 Parallel data bus, bit 6
34 38 (I/O) D5 Parallel data bus, bit 5
35 39 (I/O) D4 Parallel data bus, bit 4
36 40 (I/O) D3 Parallel data bus, bit 3
37 41 (I/O) D2 Parallel data bus, bit 2
38 42 (I/O) D1 Parallel data bus, bit 1
39 43 (I/O) D0 Parallel data bus, bit 0, LSB
This group is the parallel data bus, used to read or write parallel data.
During access to external thumbwheel switches, memory, or display, the
lower byte of the device address is presented on these lines just prior to
the data transfer. Parallel commands are also accepted by the CY545 on
these lines, using the handshake control signals. These lines are open
drain, so external pull-up resistors are required when they are used as
outputs.
DIP PLCC Pin Name Description
40 44 (I) VCC +5 Volt power supply input.

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© 2002 Cybernetic Micro Systems Chapter 3 - Command Interfaces11
Command Interfaces
The CY545 supports two basic command interfaces, a parallel interface and a serial interface.
These signals are similar to functions on other CYxxx controllers from Cybernetic Micro
Systems.
Parallel Interface
The parallel interface uses two handshake lines, IO_REQUEST and BUSY. When you wish to
send a command character to the CY545, you first check that it is not busy; the BUSY signal
should be high.
You then place the character to send on the parallel data bus lines. Be sure to drive all 8 data
lines.
Next, you drive the IO_REQUEST signal low,
indicating that a character is available
Now, wait for the CY545 to go busy, with a low
level on the BUSY signal, indicating that the
CY545 has read the command character.
Finally, you remove the character from the data
bus and drive the IO_REQUEST line high again.
This function is repeated until all command characters have been issued to the CY545. In direct
command mode, the CY545 executes every command as it is received. This means that the
CY545 will go busy for a longer period of time with the last character of a command, while the
command is actually executed. For long time delays or long motions, this time could be many
seconds.
This parallel interface is compatible to that of other CYxxx control chips. It is also compatible
with the CY233 Network Controller, so you can command several CY545s from a computer
serial port, using a CY233 as a network “front end” to each CY545.
CY545 Interface to CY233 Network Control Chip
For a CY233-based interface, the DAV signal from the CY233 is connected to the
IO_REQUEST signal of the CY545, and the ACK signal of the CY233 is connected to the BUSY
signal of the CY545. In addition, the FPL signal of the CY233 is connected to USRB6 of the
CY545, which shares the FPL function on this line. An example applications schematic,
provided with this manual, shows the connections. The relevant portion is reproduced below.
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CY545 Stepper System Controller
www.ControlChips.com
© 2002 Cybernetic Micro Systems Chapter 3 - Command Interfaces12
The CY233 Network Control chip allows you to connect up to 255 devices to a single RS-232
serial communications line such as an IBM-PC COM1 or COM2 port, with unique addresses
assigned to each device. The CY233 Network is ideal for distributed systems where central
control is required but very high speed communication is unnecessary.
The CY545 Serial Interface
The CY545 also provides a direct serial command interface, which may be connected to a host
computer or terminal. Since the CY545 signals are all TTL voltage levels, external RS-232 line
drivers and receivers must be provided, to translate the RS-232 voltage levels to the CY545
TTL levels. A Maxim MAX-233 does this function in a single chip, operating at +5 volts. This
interface is also shown on the applications schematic.
The serial interface may be operated in one of two ways, with a fixed baud rate, selected at
power up, or with an adaptive baud rate, selected by two carriage return characters from the
host.
The fixed baud rate mode is selected by tying the BUSY line low, so the CY545 will read it as a
zero value on power up. The CY545 IO_REQUEST line value will determine the baud rate as
follows:

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© 2002 Cybernetic Micro Systems Chapter 3 - Command Interfaces13
F=9600 baud
1=2400 baud
0=300 baud
When the IO_REQUEST line is left floating, 9600 baud is selected. When tied high, 2400 baud
is selected, and when tied low, 300 baud is selected. For these fixed rates to be correct, the
CY545 must be operated with an 11 MHz crystal clock. Other values will scale the baud rate
linearly by the difference in crystal frequencies.
An alternative method of selecting the baud rate is through a parallel Mode command. For this
command, nine baud rate selections are available, from 300 to 57600, plus the self adaptive
rate. Details of the Mode command are described in a later section.
Note that the selection of fixed baud rate mode through the BUSY and IO_REQUEST lines,
gives up the use of the parallel handshake interface, since the lines are used to select the baud
rate. This is fine if only the serial interface will be used. However, if both interfaces must be
used on the same CY545, the baud rate may only be set adaptively, or through a parallel Mode
command.
The adaptive serial mode is chosen by default, when the BUSY signal is left floating, so the
CY545 can drive it at power up. In this mode, the serial baud rate is not set until the CY545
receives two carriage return codes. Be sure to send these characters after power up or any
reset (hardware or software). Once the two carriage returns have been received, normal CY545
commands may be sent.
When working with the serial interface, the best crystal frequency for the CY545 is 11 MHz. This
will provide the largest baud rate operating range, with the least baud rate error. Internal timer
resolution of the CY545 will limit the available rates, especially at the high end. At 11 MHz,
standard rates up to 19200 baud may be selected. Note that other CY545 functions, such as the
step rates and time delays, have been calibrated for a 12 MHz clock source. This means these
functions will run somewhat slower when 11 MHz is used. Changes to the relevant parameter
values can compensate for some of this difference. Alternatively, a 12 MHz clock will work fine,
if the selected adaptive baud rates are always 4800 baud or less.
When operating the CY545 at 16 MHz, internal timer resolution still limits the reliable operation
of the serial interface to 4800 baud or less. The error at higher baud rates may be too great for
consistent communications.

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© 2002 Cybernetic Micro Systems Chapter 3 - Command Interfaces14
However, there is a crystal frequency of 14.7456 MHz at which the CY545 can be operated in
the adaptive mode. With this frequency, the internal resolution of the CY545 baud rate timer
allows it to adapt to all standard baud rates from 300 to 19,200 baud, plus two higher, non-
standard rates of 38,400 and 76,800 baud.
Also, the CY545 serial interface works on a fixed format character, which is always 8 data bits,
with no parity bit, and one stop bit. All 8 data bits are used to interpret the command character
values, so be sure to send the proper 8 bit codes for the various ASCII command characters.
Finally, the CY545 optionally implements a Clear to Send signal ("CTS/") which may be used by
the host system to indicate when the CY545 is busy processing a command. No additional
characters should be sent to the CY545 while CTS/ is off (TTL high). Once the CY545 has
finished processing the current command, CTS/ will be enabled again, indicating that the CY545
is ready for more serial characters. The polarity of the CY545 CTS/ signal allows it to be
connected directly to your host system CTS RS-232 signal, through a standard RS-232 line
driver. No additional logic is required.
The CTS/ signal shares functions with User Bit 6, which is also the CY233 FPL/ signal. Since
the signal has multiple functions, the CTS/ function is disabled at power on or any restart
operation. You must issue a Mode command with MBit 5 set in order to enable the CTS/ signal.
See the later section on the Mode Command for more details.

CY545 Stepper System Controller
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© 2002 Cybernetic Micro Systems Chapter 4 - Command Summary15
CY545 Command Summary
The following is a list of CY545 commands, including the command letter and argument
structure. Arguments without a suffix should be single byte numeric values up to 255, while
arguments with a "16" suffix may be two byte numbers up to 65535, and arguments with a "24"
suffix may be three byte numbers up to 16777215. Commands are entered as the single upper
case ASCII letter, followed by a space, and the argument value. Multiple arguments may be
separated by a space or comma. The command ends with a carriage return character.
Commands without arguments simply use the command letter, followed directly by the carriage
return.
Command Function
A Pos24 At position, sets current step position.
B Bit Bit set or clear of user selectable bits.
CSetContinuous step mode.
D Del16 Delay for specified milliseconds.
E Enter following commands to external memory.
F Rate Specify First or starting step rate.
G Go step. Starts relative mode stepping.
H Bit Seek Home, using specified bit.
I Initialize controller, perform software reset.
J Addr Jump to byte address of current memory page.
L Cnt,Addr Loop to byte address for specific count.
N Num24 Set Number of steps for relative motions.
O Mode Set Operating mode of CY545.
P Pos24 Step to specified absolute Position.
Q Quit entering commands to external memory.
R Rate Specify slewing or maximum step Rate.
S Slope Specify acceleration/deceleration Slope value.
T Bit,Addr Loop to address Til bit matches value.
U Reserved command.
V Reserved command.
W Bit Wait for specified bit to match value.
XEXecute external memory commands.
Y Addr16 Set external memoryaddress pointer.
Z Cnt16,Addr ZillionLoop to byte address for 16-bit count.
+ Select CW direction for relative motions.
- Select CCW direction for relative motions.
/ Negate prefix used with Bit commands.
? Cmd Query specified command parameter value.
0 Stop execution of commands from memory.
[Addr,Cnt,D1,..,Dn Special HP-display support command.
"String" Display all characters between quotes.
C
C
CH
H
HA
A
AP
P
PT
T
TE
E
ER
R
R 4
4
4
-
-
- C
C
CO
O
OM
M
MM
M
MA
A
AN
N
ND
D
D
S
S
SU
U
UM
M
MM
M
MA
A
AR
R
RY
Y
Y