m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 36

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

Fig. 2.2.4 Operation waveform examples at reading from or writing to internal area
(a) When accessing 8-bit data (Note 1) or accessing 16-bit data starting from an even-numbered address
(b) When accessing 16-bit data starting from an odd-numbered address
(c) When accessing 32-bit data starting from an even-numbered address
(d) When accessing 32-bit data starting from an odd-numbered address
Internal address bus
Internal address bus
Internal address bus
Internal address bus
RD: Data to be read, WD: Data to be written
Note 2: The above waveforms apply when bus cycle = 2 .
Internal data bus
Internal data bus
Internal data bus
Internal data bus
Internal data bus
Internal data bus
Internal data bus
Internal data bus
(AD
(DB
(AD
(DB
(AD
For the bus cycles at access to the internal area, see Table 2.2.4.
(DB
(DB
(AD
(DB
(DB
(DB
(DB
0
8
–
0
8
0
8
0
–
0
8
–
0
0
–
–
0
–
–
–
–
AD
–
–
–
DB
AD
DB
AD
DB
DB
AD
DB
DB
DB
DB
23
15
BIU
23
15
23
BIU
15
BIU
BIU
7
23
15
)
7
7
7
)
)
)
)
)
)
)
)
)
)
)
Address
Address
Address
Address
WD (even)
WD (even)
WD (odd)
WD (odd)
WD (odd)
WD (odd)
CENTRAL PROCESSING UNIT (CPU)
7905 Group User’s Manual Rev.1.0
(odd)
(even)
(odd)
(odd)
(even)
(odd)
RD
RD
RD
RD
RD
RD
Address + 1
Address + 2
Address + 1
Note 1: When reading 8-bit data at an even-numbered address, only RD (even)
WD (even)
WD (even)
WD (even)
WD (odd)
WD(odd)
will be taken into a data buffer.
When reading 8-bit data at an odd-numbered address, only RD (odd)
will be taken into a data buffer.
When writing 8-bit data to an even-numbered address, only WD (even)
will be written to the address.
When writing 8-bit data to an odd-numbered address, only WD (odd)
will be written to the address.
(even)
(even)
(even)
(odd)
(odd)
RD
RD
RD
RD
RD
Address + 3
WD (even)
2.2 Bus interface unit (BIU)
(even)
RD
2-13