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AT32F435/437
Series Reference Manual
2022.11.11
Page 528
Rev 2.03
Table 24-36
T ypical pin signals for PC card
Pin name
PC card
XMC_NCE4_1
Chip-select 1 (CE1)
XMC_NCE4_2
Chip-select 2 (CE2)
XMC_A[10:0]
Address bus
XMC_NOE
Output enable for common and attribute spaces
XMC_NWE
Write enable for common and attribute spaces
XMC_NIORD
Output enable for IO space
XMC_NIOWR
Write enable for IO space
XMC_NREG
attribute space select
XMC_D[15: 0]
Data bus
XMC_CD
PC card detection signal, active high
XMC_NWAIT
Ready/Busy (R/B)
XMC_INTR
PC card interrupt signal
Access address and Data access
The upper bytes of the HADDR bit is used to select a memory bank while the lower bytes to data memory
address. Address translation between them is shown in Table 24-5. As long as read/write access to a
specific address occurs, the XMC will enable chip-select signals and write/read operation to the external
memories according to the HADDR bit.
In case that the AHB data width is not equal to that of the memories, the XMC will make appropriate
arrangement according to the typical signals of the external memories. Table 24-37
lists the operation
modes supported by XMC.
Table 24-37
Access data width and PC card data width
Memory
Mode
AHB data size
Memory data size Description
PC card
Read/Write
8
16
Use XMC_NCE4_1
Read/Write
16
16
Use
XMC_NCE4_1
and
XMC_NCE4_2
Read/Write
32
16
Split into 2 XMC accesses and use
XMC_NCE4_1 and XMC_NCE4_2
24.5.2 Access timings
The XMC access the NAND Flash according to the timing parameters, as shown in
. Users can perform programming operations according to the specifications of the external memory
and application needs.
Table 24-38
PC card parameter register
Parameter register
Description
Access mode
Unit
CMDHIZT/ATDHIZT/IOHIZT Memory data bus high-Z time
Write
HCLK cycles
CMST/ATST/IOST
Memory setup time
Read/Write
HCLK cycles
CMWT/ATWT/IOWT
Memory wait time
Read/Write
HCLK cycles
CMHT/ATHT/IOHT
Memory hold time
Read/Write
HCLK cycles