System Architecture

Table 2-6. Pin & Signal Descriptions for the PXA255 Processor (Sheet 3 of 9)

Pin Name

Type

Signal Descriptions

Reset State

Sleep State

 

 

 

 

 

nPIOW/

ICOCZ

PCMCIA I/O write. (output) Performs write transactions

Pulled High -

Note [5]

GPIO[51]

to PCMCIA I/O space.

Note[1]

 

 

 

 

 

 

 

nPIOR/

ICOCZ

PCMCIA I/O read. (output) Performs read transactions

Pulled High -

Note [5]

GPIO[50]

from PCMCIA I/O space.

Note[1]

 

 

 

 

 

 

 

 

 

PCMCIA card enable 2. (output) Selects a PCMCIA

 

 

nPCE[2]/

 

card. nPCE[2] enables the high byte lane and nPCE[1]

Pulled High -

 

ICOCZ

enables the low byte lane.

Note [5]

GPIO[53]

Note[1]

 

MMC clock. (output) Clock signal for the MMC

 

 

 

 

 

 

 

Controller.

 

 

 

 

 

 

 

nPCE[1]/

 

PCMCIA card enable 1. (outputs) Selects a PCMCIA

Pulled High -

 

ICOCZ

card. nPCE[2] enables the high byte lane and nPCE[1]

Note [5]

GPIO[52]

Note[1]

 

enables the low byte lane.

 

 

 

 

 

 

 

 

 

 

nIOIS16/

 

IO Select 16. (input) Acknowledge from the PCMCIA

Pulled High -

 

ICOCZ

card that the current address is a valid 16 bit wide I/O

Note [5]

GPIO[57]

Note[1]

 

address.

 

 

 

 

 

 

 

 

 

 

nPWAIT/

 

PCMCIA wait. (input) Driven low by the PCMCIA card to

Pulled High -

 

ICOCZ

extend the length of the transfers to/from the PXA255

Note [5]

GPIO[56]

Note[1]

 

processor.

 

 

 

 

 

 

 

 

 

 

 

 

PCMCIA socket select. (output) Used by external

 

 

PSKTSEL/

 

steering logic to route control, address, and data signals

Pulled High -

 

ICOCZ

to one of the two PCMCIA sockets. When PSKTSEL is

Note [5]

GPIO[54]

low, socket zero is selected. When PSKTSEL is high,

Note[1]

 

 

 

 

socket one is selected. Has the same timing as the

 

 

 

 

address bus.

 

 

 

 

 

 

 

nPREG/

 

PCMCIA Register select. (output) Indicates that the

Pulled High -

 

ICOCZ

target address on a memory transaction is attribute

Note [5]

GPIO[55]

Note[1]

 

space. Has the same timing as the address bus.

 

 

 

 

 

LCD Controller Pins

 

 

 

L_DD(7:0)/

ICOCZ

LCD display data. (outputs) Transfers pixel information

Pulled High -

Note [3]

GPIO[65:58]

from the LCD Controller to the external LCD panel.

Note[1]

 

 

 

 

 

 

 

 

 

LCD display data. (output) Transfers pixel information

 

 

L_DD[8]/

ICOCZ

from the LCD Controller to the external LCD panel.

Pulled High -

Note [3]

Memory Controller alternate bus master request.

GPIO[66]

Note[1]

 

(input) Allows an external device to request the system

 

 

 

 

 

 

 

bus from the Memory Controller.

 

 

 

 

 

 

 

 

 

LCD display data. (output) Transfers pixel information

 

 

L_DD[9]/

ICOCZ

from the LCD Controller to the external LCD panel.

Pulled High -

Note [3]

GPIO[67]

MMC chip select 0. (output) Chip select 0 for the MMC

Note[1]

 

 

 

 

Controller.

 

 

 

 

 

 

 

 

 

LCD display data. (output) Transfers pixel information

 

 

L_DD[10]/

ICOCZ

from the LCD Controller to the external LCD panel.

Pulled High -

Note [3]

GPIO[68]

MMC chip select 1. (output) Chip select 1 for the MMC

Note[1]

 

 

 

 

Controller.

 

 

 

 

 

 

 

L_DD[11]/

 

LCD display data. (output) Transfers pixel information

Pulled High -

 

ICOCZ

from the LCD Controller to the external LCD panel.

Note [3]

GPIO[69]

Note[1]

 

MMC clock. (output) Clock for the MMC Controller.

 

 

 

 

 

 

 

 

 

 

L_DD[12]/

 

LCD display data. (output) Transfers pixel information

Pulled High -

 

ICOCZ

from the LCD Controller to the external LCD panel.

Note [3]

GPIO[70]

Note[1]

 

RTC clock. (output) Real time clock 1 Hz tick.

 

 

 

 

 

 

 

 

 

 

Intel® PXA255 Processor Developer’s Manual

2-11

Page 41
Image 41
Intel manual Pin & Signal Descriptions for the PXA255 Processor Sheet 3, Psktsel