Intel® PXA255 Processor Developer’s Manual
6-67
Memory Controller
Figure 6-28
shows the glue logic need for a 2-socket system. RDY/nBSY signals are routed
through a buffer to two separate GPIO pins. In the data bus transceiver control logic, nPCE1
controls the enable for the low byte lane and nPCE2 controls the enable for the high byte lane.\
Figure 6-27. Expansion Card External Logic for a One-Socket Configuration
MD<15:0>
D<15:0>
nOE
DIR
nCD<1>
nCD<2>
RDY/nBSY
A[25:0]
nREG
nCE<2:1>
nOE
nWE
nIOR
nIOW
nWAIT
nIOIS16
GPIO<w>
GPIO<x>
MA[25:0]
nPREG
nPOE
nPWE
nPIOR
nPIOW
nPWAIT
nIOIS16
nPCE<2:1>
GPIO<y>
PSKTSEL
RD/nWR
GPIO<z>
Intel® - PXA255 Processor
Socket 0
nPCD0
nPCD1
PRDY_BSY0
PADDR_EN0
5V to 3.3V or 2.5V
5V to 3.3V or 2.5V
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......