W79E648 Datasheet, PDF (32/80 Pages) Winbond – Fast 8051 Compatible microcontroller with a redesigned Processor

Preliminary W79E648
Continued
M2
M1
0
1
1
0
1
0
1
1
1
1
Machine
RD or WR
RD or WR
RD or WR
M0
Cycles
strobe width strobe width strobe width
in Clocks
@ 25 MHz
@ 40 MHz
1
5
12
480 nS
300 nS
0
6
16
640 nS
400 nS
1
7
20
800 nS
500 nS
0
8
24
960 nS
600 nS
1
9
28
1120 nS
700 nS
CLK
ALE
PSEN
WR
PORT 0
PORT 2
Last Cycle
of Previous
Instruction
First
Machine cycle
Second
Machine cycle
MOVX instruction cycle
Next Instruction
Machine Cycle
C1 C2 C3 C4 C1 C2 C3 C4 C1 C2 C3 C4 C1 C2 C3 C4
A0-A7
D0-D7
A0-A7
D0-D7
A0-A7
D0-D7
A0-A7
D0-D7
MOVX Inst.
Address
Next Inst.
Address
MOVX Data
Address
MOVX Inst.
Next Inst. Read MOVX Data out
A15-A8
A15-A8
A15-A8
A15-A8
Figure 8. Data Memory Write with Stretch Value = 0
- 32 -