PR31500 Datasheet, PDF (8/24 Pages) NXP Semiconductors – Poseidon embedded processor

Philips Semiconductors
Poseidon embedded processor
Preliminary specification
MIPS
PR31500
PIN DESCRIPTIONS
Overview
The PR31500 processor contains 208 pins consisting of input, output, bi-directional, and power and ground pins. These pins are used to
support various functions. The following sections will describe the function of each pin including any special power-down considerations for
each pin.
Pins
The PR31500 PROCESSOR contains 208 total pins, consisting of 136 signal pins, 4 spare pins, 34 power pins, and 34 ground pins. Of the 136
signal pins, 32 of them are multi-function and can be independently programmed either as IO ports or for an alternate standard/normal function.
As an IO port, any of these pins can be programmed as an input or output port, with the capability of generating a separate positive and
negative edge interrupt. See Section 2.3 for a summary of the multi-function IO ports versus their standard functions.
PIN #
NAME
Memory Pins
D(31:0)
A(12:0)
168
ALE
163
/RD
169
/WE
199
/CAS0 (/WE0)
198
/CAS1 (/WE1)
197
/CAS2 (/WE2)
195
/CAS3 (/WE3)
194
/RAS0
193
/RAS1 (/DCS1)
192
/DCS0
202
DCKE
204
DCLKIN
205
DCLKOUT
207
DQMH
208
DQML
124–126, /CS3–0
162
120–123 /MCS3–0
106, 107 /CARD2CSH,L
TYPE
NAME AND FUNCTION
I/O These pins are the data bus for the system. 8-bit SDRAMs should be connected to bits 7:0 and
16-bit SDRAMs and DRAMs should be connected to bits 15:0. All other 16-bit ports should be
connected to bits 31:16. Of course, 32-bit ports should be connected to bits 31:0. These pins are
normally outputs and only become inputs during reads, thus no resistors are required since the
bus will only float for a short period of time during bus turn-around.
O
These pins are the address bus for the system. The address lines are multiplexed and can be
connected directly to SDRAM and DRAM devices. To generate the full 26-bit address for static
devices, an external latch must be used to latch the signals using the ALE signal. For static
devices, address bits 25:13 are provided by the external latch and address bits 12:0 (directly
connected from PR31500’s address bus) are held afterward by PR31500 processor for the
remainder of the address bus cycle.
O
This pin is used as the address latch enable to latch A(12:0) using an external latch, for generating
the upper address bits 25:13.
O
This pin is used as the read signal for static devices. This signal is asserted for reads from
/MCS3-0, /CS3-0, /CARD2CS and /CARD1CS for memory and attribute space, and for reads from
PR31500 processor accesses if SHOWPR31500 is enabled (for debugging purposes).
O
This pin is used as the write signal for the system. This signal is asserted for writes to /MCS3-0,
/CS3-0, /CARD2CS and /CARD1CS for memory and attribute space, and for writes to DRAM and
SDRAM.
O
This pin is used as the CAS signal for SDRAMs, the CAS signal for D(7:0) for DRAMs, and the
write enable signal for D(7:0) for static devices.
O
This pin is used as the CAS signal for D(15:8) for DRAMs and the write enable signal for D(15:8)
for static devices.
O
This pin is used as the CAS signal for D(23:16) for DRAMs and the write enable signal for
D(23:16) for static devices.
O
This pin is used as the CAS signal for D(31:24) for DRAMs and the write enable signal for
D(31:24) for static devices.
O
This pin is used as the RAS signal for SDRAMs and the RAS signal for Bank0 DRAMs.
O
This pin is used as the chip select signal for Bank1 SDRAMs and the RAS signal for Bank1
DRAMs.
O
This pin is used as the chip select signal for Bank0 SDRAMs.
O
This pin is used as the clock enable for SDRAMs.
I
This pin must be tied externally to the DCLKOUT signal and is used to match skew for the data
input when reading from SDRAM and DRAM devices.
O
This pin is the (nominal) 73.728 MHz clock for the SDRAMs.
O
This pin is the upper data mask for a 16-bit SDRAM configuration.
O
This pin is the lower data mask for a 16-bit SDRAM or 8-bit SDRAM configuration.
O
These pins are the Chip Select 3 through 0 signals. They can be configured to support either 32-bit
or 16-bit ports.
O
These pins are the MagicCard Chip Select 3 through 0 signals. They only support 16-bit ports.
O
These pins are the Chip Select signals for PCMCIA card slot 2.
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