Intel® PXA255 Processor Developer’s Manual
6-65
Memory Controller
When writes goes to a card sockets and a byte has been masked via an internal byte enable, the
write does not occur on the external bus. For reads, one half-word is always read from the socket,
even if only 1 byte is requested. In some cases, based on internal address alignment, one word is
read, even if only 1 byte is requested.
All DMA modes are supported in the Card interface increment the address.
Table 6-31. Common Memory Space Write Commands
nPCE2 nPCE1 MA<0> nPOE nPWE
MD[15:8]
MD[7:0]
0
0
0
1
0
Odd Byte
Even Byte
1
0
0
1
0
Unimportant
Even Byte
1
0
1
1
0
Unimportant
Odd Byte
Table 6-32. Common Memory Space Read Commands
nPCE2 nPCE1 MA<0> nPOE nPWE
MD[15:8]
MD[7:0]
0
0
0
0
1
Odd Byte
Even Byte
Table 6-33. Attribute Memory Space Write Commands
nPCE2 nPCE1 MA<0> nPOE nPWE
MD[15:8]
MD[7:0]
0
0
0
1
0
Unimportant
Even Byte
1
0
0
1
0
Unimportant
Even Byte
1
0
1
1
0
Unimportant
Unimportant
Table 6-34. Attribute Memory Space Read Commands
nPCE2 nPCE1 MA<0> nPOE nPWE
MD[15:8]
MD[7:0]
0
0
0
0
1
Unimportant
Even Byte
Table 6-35. 16-Bit I/O Space Write Commands (nIOIS16 = 0)
nPCE2 nPCE1 MA<0> nPIOR nPIOW
MD[15:8]
MD[7:0]
0
0
0
1
0
Odd Byte
Even Byte
1
0
0
1
0
Unimportant
Even Byte
1
0
1
1
0
Unimportant
Odd Byte
Table 6-36. 16-Bit I/O Space Read Commands (nIOIS16 = 0)
nPCE2 nPCE1 MA<0> nPIOR nPIOW
MD[15:8]
MD[7:0]
0
0
0
0
1
Odd Byte
Even Byte
Содержание PXA255
Страница 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Страница 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Страница 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Страница 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Страница 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Страница 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Страница 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Страница 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Страница 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
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