ZiLOG Z80 series User manual

Z80
Z80 PIO PIO Module Module
For
For RC2014 RC2014
User
User Guide Guide
For
For module: module: SC103 SC103 version version 1.0 1.0
Design andDocumentation by Stephen C Cousins Edition 1.0.0

1
CONTENTS
OVERVIEW................................................................................................................2
PRINTED CIRCUIT BOARD............................................................................................. 3
SCHEMATIC...............................................................................................................4
WHAT YOU NEED.......................................................................................................5
COMPONENTS: WHAT THEY DO& WHERE TOGET THEM..................................................7
ASSEMBLY GUIDE.....................................................................................................15
CONFIGURING THE PIO MODULE.................................................................................26
ADDRESS SELECTION................................................................................................. 27
PURCHASING THE PRINTED CIRCUIT BOARD....................................................................29
FAULT FINDING........................................................................................................31
HISTORY.................................................................................................................32
CONTACT INFORMATION............................................................................................33

2
Overview
The Z80 PIOmodule (SC103) provides two 8-bit parallel ports with handshakingand
flexible input and output connectivity, as well as support for Z80 mode 2 interrupt
daisychaining.
Each port haseight bidirectional data linesand two handshaking lines. The PIO has
flexible interruptgeneration and fully supports Z80mode 2 interrupts.
For full details of the Z80 PIO see the Zilogdata sheet.

3
Printed Circuit Board
The printed circuit board is a standard footprint RC2014 board.
Printed circuit board,top/component side:
Printed circuit board,bottom/solder side:

4
Schematic
Errata
Version 1.0 of the PCB has the RC2014 IEI (pin 38) and IEO (pin 39) incorrectly
labelled.The labels are incorrectly shownnext to pins37 and 38, not38 and 39.
Also port A I/O linesare not correctly labelled on the back of the board. The labels
on the frontof the board are correct though.

5
What You Need
The following components are required to assemble the module. Header pins JP1
and JP2,and P1 to P4 may need to be cut from longerstrips.
Image Qty Reference Description
1PCB Printed circuit board SC103 Z80 PIO
4C1, 2, 3, 4 Capacitor 100nF, ceramic, leadspacing = 2.54mm
1C5 Capacitor 100uF, electrolytic, lead spacing =
2.54mm (radial) or 14mm (axial)
1JP1 and JP2 Pin header, male, 2 rows x 2 pins, straight
2JP1 and JP2 Jumper shunt for pinspacing = 2.54mm
1P1 Pin header, male, 2rows x 39 pins, angled (2nd
rowoptional)
1P2 Pin header, male, 2rows x 13 pins, angled
1P3 Pin header, male, 1row x 29 pins, angled
1P4 Pin header, male, 1row x 2 pins, angled
1RP1 Resistor pack 8x10k, SIL, 9-pin
1SW1 DIP switch,6 way, piano style
1U1 74HCT688, 8-bit identity comparator, PDIP 20
1U1 socket 20 pin PDIP IC socket 0.3" wide

6
1U2 Z80 PIO, 8MHz, Z84C2008PEG (or Z80PIO, 10MHz,
Z84C2010PEG), PDIP40
1U2 socket 40 pin PDIP IC socket 0.6" wide
1U3 74HCT08, quad2-input AND gate
1U3 socket 14 pin PDIP IC socket 0.3" wide
Also required to assemble the module from the above components:

Long
nose
pliers
Side cutters
Solderingiron
Solder
PCB cleaningmaterials

7
Components: What They Do & Where To Get Them
Each componentis described below. I have listed multiple sources for most
components, but have not actually tried all of them,so best treat the specified part
numbers as guidance only.Where eBay is listed as a supplier, the part is likely to be
cheaper there than the other sources, sometimes considerably cheaper. Further
savings are usually possible by ordering parts direct from countries like China.
PCB
Image Qty Reference Description
1PCB Printed circuit board SC103 Z80 PIO
Supplier Partnumber
EasyEDA SearchEasyEDA.comfor RC2014 PIO
The PCB is currently only availableto be ordered from EasyEDA.com, although you
can download the Gerber and send it to your preferred manufacturer.
C1, 2, 3, 4
Image Qty Reference Description
4C1, 2, 3, 4 Capacitor 100nF, ceramic, leadspacing = 2.54mm
Supplier Partnumber
Farnell 1100533
Mouser 75-1C10Z5U104M050R
RS 699-5027
These capacitors provide power supply decoupling(or bypass). The fast switching in
digitalcircuits createsspikes on the power supplylines which are suppressed with
decoupling capacitors placed at key points on the circuit board.

8
C5
Image Qty Reference Description
1C5 Capacitor 100uF, electrolytic, lead spacing =
2.54mm (radial) or 14mm (axial)
Supplier Partnumber
Farnell 9452478 (100uF, 16V,radial)
Mouser 140-REA101M1CBK0611P (100uF, 16V,radial)
RS 711-0933 (100uF, 16V, radial)
This capacitor provides suppression of transientson the power supply. The PIO
modulemay well be used to power and control external electronics, in which case
there couldbe significant transients generated on the supply lines. Where possible
supply transients should be suppressedat source, so this component shouldnot be
critical.
The PCB allows for a radial or axial capacitors. In order to build a low profile board,
the capacitor should lay on its side. An axial capacitor would be most secure in this
configuration, but there is limited length allocated and you probably don’t have one!
JP1 and JP2
Image Qty Reference Description
1JP1 and JP2 Pin header, male, 2 rows x 2 pins, straight
Supplier Partnumber
eBay 200906546562 (2x40 pin to be cut to length)
Farnell 2356151 (2x40 pin to be cut to length)
Mouser 710-61308021121 (2x40 pin to be cut to length)
RS 155-721 (2x40 pin to be cut to length)
This pairof jumpers allow the interrupt daisy chain signals to be connected to the
RC2014 bus signalUSER 2 (pin38) and USER 3 (pin39). To makeuse ofthis feature
you must use a backplane that is specifically designed to provide the necessary daisy
chain,such as Backplane SC107. The current official RC2014 backplanes do not
supportthis feature.
Alternativelythe signals IEI and IEO can be foundon connector P2 on the backedge
of the board. Dupont wires can be used to daisy chain these signals to other
modules.

9
JP1 and J2
Image Qty Reference Description
2JP1 and JP2 Jumper shunt for pinspacing = 2.54mm
Supplier Partnumber
eBay 201261690156
Farnell 2396303
Mouser 649-68786-102LF
RS 674-2397
These shunts (smallsockets) connect the required pins on JP1 and J2.
P1
Image Qty Reference Description
1P1 Pin header, male, angled, 2-row x 39-pin, 2 row (1 rowoptional)
Supplier Partnumber
eBay 200906546562 (2x40 pin to be cut to length)
Farnell 1097962 (2x40 pin to be cut to length)
Mouser 571-9-103795-0 (2x40 pin to be cut to length)
RS 155-743 (2x40 pin to be cut to length)
This connector mateswith the RC2014 bus backplane. You can fit a single or a
double row header. The only reasons for the secondrow is to provide additional
power supply pins, make the modulethe same height as the othersand to increase
stability of the module.
Somepins need to be removed, using a pair of pliers, before fitting.

10
P2
Image Qty Reference Description
1P2 Pin header, male, 2rows x 13 pins, angled
Supplier Partnumber
eBay 200906546562 (2x40 pin to be cut to length)
Farnell 1097962 (2x40 pin to be cut to length)
Mouser 571-9-103795-0 (2x40 pin to be cut to length)
RS 155-743 (2x40 pin to be cut to length)
This connector provides access to all the PIO I/O signals in a format suitable to
connect to external devices via a ribbon cable. See schematic for pin-out.
P3
Image Qty Reference Description
1P3 Pin header, male, 1rows x 29 pins, angled
Supplier Partnumber
eBay 200906546562 (1x40 pin to be cut to length)
Farnell 2356192 (1x40 pin to be cut to length)
Mouser 710-61304011021 (1x40 pin to be cut to length)
RS 156-077 (1x40 pin to be cut to length)
This connector provides access to all the PIO I/O signals in a format suitable to
connect to breadboardsand other prototypingprojects via Dupontwires.
This connector is optional, so if you want to put the RC2014 in a case or just don’t
like the look of it, you can leavethis connector off. Alternatively you might prefera
different connector, such as afemaleheadersocket.
Pin 15 is a ground terminal between the two port I/O connections. You maywish to
removethis pin before assembly, so that it is easierto visually identify required
connections. See schematicfor pin-out.

11
P4
Image Qty Reference Description
1P4 Pin header, male, angled, 1-row x 2-pin
Supplier Partnumber
eBay 200906546562 (1x40 pin to be cut to length)
Farnell 2356192 (1x40 pin to be cut to length)
Mouser 710-61304011021 (1x40 pin to be cut to length)
RS 156-077 (1x40 pin to be cut to length)
As the official RC2014 backplanesdo not provide a Z80 mode 2interrupt daisy chain
(IEI and IEO signals), these havebeen brought to the backof the board where they
canbe easily linkedto other modules with Dupontwires.
RP1
Image Qty Reference Description
1RP1 Resistor pack 8x10k, SIL, 9-pin
Supplier Partnumber
Farnell 9356819
Mouser 652-4609X-1LF-10K
RS 333-864
This isa network of 8 resistors with oneend of eachresistor common to pin1. The
resistors are used to pull up the address select switch (SW1) outputs and also to pull
up the interrupt enableinput signal (IEI).

12
SW1
Image Qty Reference Description
1SW1 DIP switch,6 way, piano style
Supplier Partnumber
eBay 262361463572
Farnell 2452331
Mouser 653-A6FR-6104(black)
RS 877-2359
This switch is used to set the I/O address for the module. It sets the required state of
address linesA2 to A7, thus allowing the module tooccupya 4 address block onany
4-byteboundary.
In order to provide some certainty for software it is strongly recommended you set
the base address of your first PIO module to 0x68, so that the module occupies I/O
addresses 0x68to 0x6B. This is doneby settingswitches1 to6, to On,Off, Off,On,
Off,On where On is the switchclosed. In the case of the piano style DIP switch, the
On position is the switch lever pushed down towardsthe circuit board.
Switchesin the On positionpull down the input of the address comparatorU1.
Switchesin the Off position allow the input of the address comparator tobe pulled
up by RP1.
U1
Image Qty Reference Description
1U1 74HCT688, 8-bit identity comparator, PDIP 20
Supplier Partnumber
Farnell 2407104
Mouser 595-CD74HCT688E
RS 663-0650
This integrated circuit provides the address decoding, by comparing the current
address from theCPU with the address set with the DIP switch SW1.

13
U1 socket
Image Qty Reference Description
1U1 socket 20 pin PDIP IC socket 0.3"
Supplier Partnumber
Farnell 4285608
Mouser 571-1-2199298-6
RS 674-2444
U2
Image Qty Reference Description
1U2 Z80 PIO, 8MHz, Z84C2008PEG (or Z80PIO, 10MHz, Z84C2010PEG), PDIP40
Supplier Partnumber
Farnell 6MHzversiononly
Mouser 692-Z84C4008PEG(8 MHzversion)
692-Z84C4010PEG(10MHzversion)
RS 625-9040 (8 MHz version)
The Z80 PIOprovidesprovidestwo 8-bit parallel ports with handshaking and flexible
interrupt functions. It has mode 2 interrupt support, makingit a usual general
purpose I/O chip for use in an expanded Z80system.
For furtherdetails see the Zilog PIO data sheet.
U2 socket
Image Qty Reference Description
1U2 socket 40 pin PDIP IC socket 0.6"
Supplier Partnumber
Farnell 4285669
Mouser 571-1-2199299-5 or 649-DILB40P223TLF
RS 674-2466

14
U3
Image Qty Reference Description
1U3 74HCT08, quad2-input AND gate
Supplier Partnumber
Farnell 9591796
Mouser 595-CD74HCT688E
RS 527-514
This integrated circuit provides a specialreset signal to the PIO. There is no separate
reset pin on the PIO, so instead the M1 pin has an extra function. When M1 is low
and both RD and IORQ are high,the PIO enters a reset state.
U3 socket
Image Qty Reference Description
1U3 socket 14 pin PDIP IC socket 0.3"
Supplier Partnumber
Farnell 2445621
Mouser 571-1-2199298-3
RS 674-2438

15
Assembly Guide
This guide assumes you are familiar withassembling circuit boards,soldering and
cleaning. If not, it is recommended you read some of the guides on the internet
before continuing.
First check you have all the required components, as listed in the section“What You
Need”. Header pins JP1 and JP2, and P1 to P4 may need to be cut from longerstrips.
Step1
Fit
and
solder
IC
sockets
for
U1,
U2
and
U3.
Be sure to fit them with the notch matching the legend on the circuit board, so you
do not end upfitting the IC the wrongway round too.

16
Step2
Fit and solder capacitors C1, C2, C3 and C4.
These can be fitted either way round, as they are not polarity dependent.

17
Step3
Fit and solder resistor packRP1.
This must be fitted the correct way round.The component
should
have
pin
1
marked
with
a
dot,
as
illustrated
right.

18
Step4
Fit and solder connector P1.
You can fit just a single rowheader as used by the RC2014 standard bus. The only
reasons for the second row is to provideadditional power supply pins, make the
modulethe same height as the others and to increase stability of the module.
To prepare the header, it should first be cut
to length(if starting with a strip more than
39pins long)and thenunwanted pinsmust
be
removed.
If
you
want
to
make
the
board
as
easy
to
insert
and
remove
as
possible,
you
canremove all the pins in the second row
exceptthose shown on the schematicas
used and indicated below in green.
Take care to ensure the pinsare parallel to the circuit board so that the board willbe
vertical whenplugged intoa backplane.

19
Step5
Fit and solder connector P2.
Take care to ensure the pinsare parallel to the circuit board.