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Figure 6-29 – Intel PXA255 User Manual

Page 249

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Intel® PXA255 Processor Developer’s Manual

6-67

Memory Controller

6.8.5

Expansion Card Interface Timing Diagrams and Parameters

Figure 6-29

shows a 16-bit access to a 16-bit memory or I/O device. When common memory is

accessed, the MCMEM0 and MCMEM1 registers are used, depending on whether card socket 0 or
1 is addressed. MCIO0 and MCIO1 are used for I/O accesses and MCATT0 and MCATT1 are used
for access to attribute memory.

Figure 6-29. 16-Bit PC Card Memory or I/O 16-Bit (Half-word) Access

x_ASST_HOLD

x_ASST_WAIT + wait states

x_HOLD

x_SET

0ns

50ns

100ns

150ns

MEMCLK

MA,nPREG,PSKTSEL

nPCE2,nPCE1

nPWE,nPOE,nPIOW,nPIOR

RDnWR

nIOIS16

nPWAIT

read_data

write_data