
Section 3
Hardware Architecture Hardware Modules
3.4 Synchronous Dual-Port RAM
(DPRAM)
The PCI 9030 is connected to two (2)
Synchronous Dual-Port RAMs (U7 and U8) on
the RDK board. These DPRAMs are 3.3V, 9 ns,
4Kx18 Cypress memory. But the board is
assembled with one DPRAM (U7) on board as
default.
The DPRAM serves two purposes on the RDK
board. First, with simple interface logic that
resides in the 5ns, 20-pin programmable GAL
device, the left port of DPRAM U7 connects to
the lower 16-bit data bus of the PCI 9030. A PCI
bus master can perform 16-bit single memory
cycles with the DPRAM through the PCI 9030. If
the PCI bus master supports the burst, the PCI
master can perform 16-bit continuous burst
memory cycles with the DPRAM also. Second,
the PCI 9030 is a PCI target chip with an output
only address bus. If a designer’s design has a
microprocessor or microcontroller, they can
place these devices on the separate bus on the
right port of the DPRAM. Also, if the designer
wants to have 32-bit DPRAM, they can add the
same Cypress chip to the U8 footprint and
rearrange the resistor networks RN20 - RN25.
(See page 4 of the Schematics for more details.)
The interface between the PCI 9030 and the
DPRAMs is very straightforward. The left port of
the DPRAM is configured in pipelined mode.
Three control input signals, chip enable 1
(CE1L), counter enable (CNTENLL), and output
enable (OELL) are enabled and the counter
reset signal (CNTRSTL) is disabled with related
pull-up and pull-down resistors. Only two
control-input signals, address strobe (DPADSL)
and chip enable (CE0L) are converted from PCI
9030 control signals. If the PCI 9030 local clock
is running at 60MHz, the PCI 9030 needs two
wait states for the single memory read cycle and
the first memory read of burst memory read
cycles and zero wait state for the single or burst
write cycle.
On the right port of the DPRAMs, all the input
control signals are preset to idle states. A 29x2
header, J3, provides access to address, data,
and control signals on the right port and nearby
prototyping pads that provide the connections to
custom designs in the separate bus on the right
port of the DPRAMs.
3.5 Test Headers
Six logic analyzer headers are implemented with
the standard 0.1”, 2x10 Hewlett Packard
configuration. In this RDK, they serve two
different functions. One is for easy probing. All
PCI 9030 Local bus signals, configuration and
status signals are well arranged within these
headers. Headers LAH1 and LAH2 contain
Local bus address signals. Headers LAH3 and
LAH4 contain Local bus data signals (or
multiplexed address/data signals in the
multiplexed mode). Headers LAH5 and LAH6
carry Local bus control and status signals.
Second, these headers are centered on 0.1” grid
spacing. Designers can use these headers to
connect to a standard prototyping board for
additional prototyping. The headers do not
provide any power source; therefore, this must
be connected separately for prototyping
daughterboards.
3.6 PLX Option Module Connector
The PLX Option Module Connector resides
directly on the 32-bit multiplexed mode Local
Bus. A slave device may be connected to this
connector. A programmable chip select, CS1L,
is used to select the option module. And a
hardware interrupt, INTi1, is used for the option
module to generate an interrupt to the PCI bus
master through the PCI 9030. The schematic
provides information for all of the 100-pin
connector signals. If desired, this connector can
be used for expansion and prototyping.
3.7 Hardware Modules
The RDK-LITE provides four hardware modules:
1) RS232 serial port, 2) debug and status LEDs,
3) reset circuitry, and 4) flash ROM socket. This
is in addition to the clock generator used to
provide up to 60MHz Local bus clock to the PCI
9030, synchronous Dual-Port RAM, and POM
connector.
3.7.1RS232 Serial Port
The RS232 Serial Port combines a DB9 male
connector, a 3-output / 5 input DTE transceiver
and an UART. The serial port provides the
parallel interface to the PCI 9030 Local bus or
the separate bus at the dual-port memory.
PCI 9030RDK-LITE Hardware Reference Manual v1.3
3-6 © 2004 PLX Technology, Inc. All rights reserved.