Figure 4.16-5 Relationship Between Internal Register And External Data Bus For Byte Access; Figure 4.16-6 Relationship Between Internal Register And External Data Bus For 16-Bit Bus Width - Fujitsu MB91F109 FR30 Hardware Manual

CHAPTER 4 BUS INTERFACE
Byte access (during execution of LDUB and STB instructions)

Figure 4.16-5 Relationship between Internal Register and External Data Bus for Byte Access

(a) Lower bits of output address "0"
Internal register
Data Bus Width
The following shows the relationship between the internal register and external data bus for
each data bus width.
16-bit bus width

Figure 4.16-6 Relationship between Internal Register and External Data Bus for 16-bit Bus Width

142
External bus
D31
D31
AA
D23 D23
D15
D07
AA
Internal register
Lower part of the output address
D31
D23
D15
D07
(b) Lower bits of output address "1"
Internal register
D31
D23
D15
D07
AA
External bus
"00" "10"
AA Read/Write AA CC
BB BB DD
CC
DD
External bus
D31
D23
AA
D31
D23