DS80C320-ECD DALLAS [Dallas Semiconductor], DS80C320-ECD Datasheet - Page 88

• Manufacturer Part Number: DS80C320-ECD
• Description: High-Speed Microcontroller User Guide
• Manufacturer: DALLAS [Dallas Semiconductor]

Note that the first Stretch value does not follow the pattern of adding four clocks to the strobe. This is
because the first Stretch uses one clock to create additional set-up and one clock to create additional hold
time. Systems using a Stretch cycle of zero are presumed to be fast enough or to be running at a slower
clock speed. Since the Stretch is based on crystal timing, the resulting pulse widths must be viewed on
the basis of the real system timing.
DATA MEMORY CYCLE STRETCH VALUES Table 6-1
Note: These numbers represent nominal values. Actual timing may vary slightly.
FULL SPEED MOVX INSTRUCTION Figure 6-4
M2
0
0
0
0
1
1
1
1
CKCON.2-0
M1
PSEN
0
0
1
1
0
0
1
1
WR
ALE
CLK
PORT 0
PORT 2
C1
M0
0
1
0
1
0
1
0
1
Last Cycle of
Instruction
C2
Previous
Instruction
Address
MOVX
A0-A7
C3
A8-A15
MEMORY
C4
3 (default)
CYCLES
Instruction
MOVX
D0-D7
DATA MEMORY WRITE (2 CYCLE, STRETCH=0)
2
4
5
6
7
8
9
C1
C2
Machine
Instruction
Cycle
Address
First
A0-A7
Next
C3
88 of 175
MOVX Instruction
A8-A15
C4
Instruction
D0-D7
Read
Next
IN CLOCK
C1
12
16
20
24
28
2
4
8
C2
Machine
Second
Cycle
Address
RD OR WR STROBE WIDTH
MOVX
A0-A7
Data
C3
High-Speed Microcontroller User’s Guide
A8-A15
C4
MOVX
t @ 25 MHz
D0-D7
Data
1120 ns
C1
160 ns
320 ns
480 ns
640 ns
800 ns
960 ns
80 ns
Instruction
Machine
C2
Cycle
Next
A0-A7
C3
A8-A15
C4
t @ 12 MHz
A0-A7
1000 ns
1333 ns
1667 ns
2000 ns
2333 ns
167 ns
333 ns
667 ns