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GD32F10x User Manual
609
needed, EXMC_NPATCFGx has to be configured.
2.
Send the command of NAND Flash read operation to the common space. Namely, during
the valid period of EXMC_NCE and EXMC_NWE, when EXMC_CLE (EXMC_A[16])
becomes valid (high level), data on the I/O pins is regarded as a command by NAND
Flash.
3.
Send the start address of read operation to the common space. During the valid period
of EXMC_NCE and EXMC_NWE, when EXMC_ALE (EXMC_A[17]) becomes valid (high
level), the data on the I/O pins is regarded as an address by NAND Flash.
4.
Waiting for NAND ready signal. In this period, NAND controller will maintain EXMC_NCE
valid.
5.
Read data byte by byte from the data area of the common space.
6.
If new commands or address haven’t been written, data of the next page can be read
out automatically. You can also read the data of the next page by going to step 3 and
then writing a new address or writing a new command and address in step 2.
NAND Flash pre-wait functionality
Some NAND Flash requires that the controller should wait for NAND Flash to be busy after
the first command byte following the address bytes are sent, and some EXMC_NCE-sensitive
NAND Flash also requires that the EXMC_NCE must remain valid before it is ready.
Taking TOSHIBA128 M x 8 bit NAND Flash as an example:
Figure 20-24. Access to none
"NCE don’t care" NAND Flash
Address Latch
Enable
(EXMC_A[17])
Write Enable
(EXMC_NWE)
Chip Enable
(EXMC_NCE)
Command Latch
Enable
(EXMC_A[16])
Output Enable
(EXMC_NOE)
Data
(EXMC_D[7:0])
Ready
(EXMC_INT[x])
tWB
tR
CMD 0
(00h)
CMD 1
30h
ADD 0
(CA0-7)
ADD 1
(CA8-11)
ADD 2
(PA0-7)
ADD 3
(PA8-15)
1.
Write CMD0 into NAND Flash bank common space command area.
2.
Write ADD0 into NAND Flash bank common space address area.
3.
Write ADD1 into NAND Flash bank common space address area.
4.
Write ADD2 into NAND Flash bank common space address area.
5.
Write ADD3 into NAND Flash bank common space address area.
6.
Write CMD1 into NAND Flash bank attribute space command area.
In step 6, EXMC uses the operation timing defined in EXMC_NPATCFGx register. After a
Summary of Contents for GD32F10 Series
Page 63: ...GD32F10x User Manual 63 programmed during the chip production ...
Page 117: ...GD32F10x User Manual 117 010 1 0 011 0 9 ...
Page 416: ...GD32F10x User Manual 416 shadow register updates every update event ...
Page 427: ...GD32F10x User Manual 427 value ...
Page 518: ...GD32F10x User Manual 518 These bits are not used in SPI mode ...