W90N745CD Datasheet, PDF (35/422 Pages) Winbond – 16/32-bit ARM microcontroller

W90N745CD/W90N745CDG
Figure 6.2.5 CPU registers Read/Write with external memory
Table 6.2.3 and Table 6.2.4
Using big-endian and word access, Program/Data path between register and external memory
WA = Address whose LSB is 0,4,8,C X = Don’t care
nWBE [1-0] / SDQM [1-0] = A means active and U means inactive
Table 6.2.3 Word access write operation with Big Endian
ACCESS OPERATION
WRITE OPERATION (CPU REGISTER Î EXTERNAL MEMORY)
XD WIDTH
HALF WORD
BYTE
Bit Number
CPU Reg Data
SA
Bit Number
SD
Bit Number
ED
XA
nWBE [1-0] /
SDQM [1-0]
Bit Number
XD
Bit Number
Ext. Mem Data
Timing Sequence
31 0
ABCD
WA
31 0
AB CD
15 0
15 0
AB
CD
WA
WA+2
AA
AA
15 0
AB
15 0
AB
1st write
15 0
CD
15 0
CD
2nd write
70
A
WA
XA
70
A
70
A
1st write
31 0
ABCD
WA
31 0
ABCD
70
70
B
C
WA+1
WA+2
XA
XA
70
B
70
B
2nd write
70
C
70
C
3rd write
70
D
WA+3
XA
70
D
70
D
4th write
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