Advantech RISC SOM-A2558 Series, Руководство пользователя

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User’s Manual for Advantech SOM-A2558 series module V1.00
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to the output enables of memory
devices to control data bus drivers.
B7 ADDR20 O SoC PXA255 system address 20 No pulling
A7 nBUF_WE O
Memory write enable. Connect to the
write
enables of memory devices.
No pulling
B8 ADDR22 O SoC PXA255 system address 22 No pulling
A8
BUF_RD_nW
R
O
Read/Write for static interface.
Signals that the current transaction
is a read or write.
No pulling
B9 GND P Ground -
A9 BUF_RDY I
Variable Latency I/O Ready pin.
Notifies the memory controller when
an external bus device is ready to
transfer data.
Pull high
with
100Kohm
B10 DATA15 IO SoC PXA255 system data 15 No pulling
A10 DATA14 IO SoC PXA255 system data 14 No pulling
B11 DATA13 IO SoC PXA255 system data 13 No pulling
A11 DATA12 IO SoC PXA255 system data 12 No pulling
B12 DATA11 IO SoC PXA255 system data 11 No pulling
A12 DATA10 IO SoC PXA255 system data 10 No pulling
B13 DATA9 IO SoC PXA255 system data 9 No pulling
A13 DATA8 IO SoC PXA255 system data 8 No pulling
B14 DATA31 IO SoC PXA255 system data 31 No pulling
A14 DATA30 IO SoC PXA255 system data 30 No pulling
B15 DATA29 IO SoC PXA255 system data 29 No pulling
A15 DATA28 IO SoC PXA255 system data 28 No pulling
B16 DATA27 IO SoC PXA255 system data 27 No pulling
A16 DATA26 IO SoC PXA255 system data 26 No pulling
B17 DATA25 IO SoC PXA255 system data 25 No pulling
A17 DATA24 IO SoC PXA255 system data 24 No pulling
B18
nBUF_SDRA
S
O
SDRAM RAS. Connect to the row
address strobe (RAS) pins for all
banks of SDRAM.
No pulling
A18
nBUF_SDCS
0
O
SDRAM CS for bank 0. Connect to
the chip select (CS) pin for SDRAM.
For the PXA255 processor
nBUF_SDCS0 can be Hi-Z.
No pulling
B19 BUF_DQM0 O
SDRAM DQM for data byte 0.
Connect to the data output mask
enables (DQM) for SDRAM.
No pulling
A19 BUF_DQM2 O
SDRAM DQM for data byte 2.
Connect to the data output mask
enables (DQM) for SDRAM.
No pulling
B20 BUF_DQM3 O
SDRAM DQM for data byte 3.
Connect to the data output mask
enables (DQM) for SDRAM.
No pulling
A20 nBUF_PWAIT I
PCMCIA wait. (input) Driven low by
the PCMCIA card to extend the Pull high
with