W90N745CD Datasheet, PDF (36/422 Pages) Winbond – 16/32-bit ARM microcontroller

W90N745CD/W90N745CDG
Table 6.2.4 Word access read operation with Big Endian
ACCESS OPERATION
READ OPERATION (CPU REGISTER Í EXTERNAL MEMORY)
XD WIDTH
Bit Number
CPU Reg Data
SA
Bit Number
SD
Bit Number
ED
XA
HALF WORD
31 0
CDAB
WA
31 0
CD AB
31 0
CD XX
31 0
CD AB
WA
WA+2
31 0
DXXX
WA
BYTE
31 0
DCBA
WA
31 0
DCBA
31 0 31 0
DCXX DCBX
WA+1
WA+2
31 0
DCBA
WA+3
SDQM [1-0]
Bit Number
XD
Bit Number
Ext. Mem Data
Timing Sequence
AA
15 0
CD
15 0
CD
1st read
AA
15 0
AB
15 0
AB
2^nd read
XA
70
D
70
D
1st read
XA
70
C
70
C
2nd read
XA
70
B
70
B
3rd read
XA
70
A
70
A
4th read
Table 6.2.5 and Table 6.2.6
Using big-endian and half-word access, Program/Data path between register and external memory.
HA = Address whose LSB is 0,2,4,6,8,A,C,E X = Don’t care
nWBE [1-0] / SDQM [1-0] = A means active and U means inactive
Table 6.2.5 Half-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
31 0
ABCD
31 0
ABCD
SA
HA
HA
Bit Number
SD
Bit Number
ED
31 0
CD CD
31 0
CD CD
31 0
CD CD
70
C
31 0
CD CD
70
D
XA
HA
HA
HA+1
nWBE [1-0] /
SDQM [1-0]
Bit Number
XD
Bit Number
Ext. Mem Data
Timing Sequence
AA
15 0
CD
15 0
CD
XA
70
C
70
C
1st write
XA
70
D
70
D
2nd write
Publication Release Date: September 22, 2006
- 31 -
Revision A2