DocID025202 Rev 7
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RM0365
Flexible static memory controller (FSMC)
286
I/O space timing register 4 (FMC_PIO4)
Address offset: 0xB0
Reset value: 0xFCFCFCFC
The FMC_PIO4 read/write registers contain the timing information used to access the I/O
space of the 16-bit PC Card/CompactFlash.
Bits 31:24
ATTHIZ:
Attribute memory x data bus Hi-Z time
Defines the number of HCLK clock cycles during which the data bus is kept in Hi-Z after the
start of a PC CARD/NAND Flash write access to attribute memory space on socket x. Only
valid for write transaction:
0000 0000: 0 HCLK cycle
1111 1110: 255 HCLK cycles
1111 1111: Reserved
Bits 23:16
ATTHOLD:
Attribute memory x hold time
Defines the number of HCLK clock cycles for write access and HCLK (+2) clock cycles for
read access during which the address is held (and data for write access) after the command
deassertion (NWE, NOE), for NAND Flash read or write access to attribute memory space on
socket:
0000 0000: reserved
0000 0001: 1 HCLK cycle for write access / 3 HCLK cycles for read access
1111 1110: 254 HCLK cycles for write access / 256 HCLK cycles for read access
1111 1111: Reserved.
Bits 15:8
ATTWAIT:
Attribute memory x wait time
Defines the minimum number of HCLK (+1) clock cycles to assert the command (NWE, NOE),
for PC Card/NAND Flash read or write access to attribute memory space on socket x. The
duration for command assertion is extended if the wait signal (NWAIT) is active (low) at the
end of the programmed value of HCLK:
0000 0000: reserved
0000 0001: 2 HCLK cycles (+ wait cycle introduced by deassertion of NWAIT)
1111 1111: 256 HCLK cycles (+ wait cycle introduced by the card deasserting NWAIT)
Bits 7:0
ATTSET:
Attribute memory x setup time
Defines the number of HCLK (+1) clock cycles to set up address before the command
assertion (NWE, NOE), for PC CARD/NAND Flash read or write access to attribute memory
space on socket x:
0000 0000: 1 HCLK cycle
1111 1110: 255 HCLK cycles
1111 1111: Reserved.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
IOHIZx
IOHOLDx
IOWAITx
IOSETx
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