w77e58 Winbond Electronics Corp America, w77e58 Datasheet - Page 42

• Manufacturer Part Number: w77e58
• Description: 8 Bit Microcontroller
• Manufacturer: Winbond Electronics Corp America

of the CPU was held for the desired period. There is no effect on any other instruction or its timing. By
default, the Stretch value is set at 1, giving a MOVX instruction of 3 machine cycles. If desired by the
user the stretch value can be set to 0 to give the fastest MOVX instruction of only 2 machine cycles.
Table 4. Data Memory Cycle Stretch Values
M2
0
0
0
0
1
1
1
1
PORT 0
PORT 2
M1
PSEN
CLK
ALE
WR
0
0
1
1
0
0
1
1
M0
C1
MOVX Inst.
Address
of Previous
Last Cycle
Instruction
A0-A7
C2
0
1
0
1
0
1
0
1
Figure 8. Data Memory Write with Stretch Value = 0
C3
A15-A8
MOVX Inst
C4
D0-D7
Machine
Cycles
3(default)
C1
2
4
5
6
7
8
9
Machine cycle
.
Next Inst.
Address
C2
A0-A7
First
MOVX instruction cycle
- 42 -
C3
A15-A8
Next Inst. Read
strobe width
in Clocks
RD or WR
C4
D0-D7
C1
12
16
20
24
28
2
4
8
MOVX Data
Machine cycle
Address
A0-A7
C2
Second
C3
A15-A8
Preliminary W77E58
MOVX Data out
D0-D7
C4
strobe width
RD or WR
@ 25 MHz
C1
1120 nS
160 nS
320 nS
480 nS
640 nS
800 nS
960 nS
Next Instruction
80 nS
Machine Cycle
A0-A7
C2
C3
A15-A8
C4
D0-D7
strobe width
RD or WR
@ 40 MHz
100 nS
200 nS
300 nS
400 nS
500 nS
600 nS
700 nS
50 nS