W79E225A Datasheet, PDF (83/200 Pages) Winbond – 8-bit Microcontroller

Preliminary W79E225A/227A Data Sheet
CLK
ALE
PSEN
AD7-0
PORT 2
Instruction Fetch
C1
C2
C3
C4
Operand Fetch
C1
C2
C3
C4
PC
OP-CODE
Address A15-8
PC+1
OPERAND
Address A15-8
Figure 8-2: Two Cycles Instruction Timing
Instruction Fetch
Operand Fetch
Operand Fetch
C1 C2 C3 C4 C1
C2 C3 C4 C1
C2 C3 C4
CLK
ALE
PSEN
AD7-0
A7-0 OP-CODE
A7-0 OPERAND
A7-0 OPERAND
PORT 2
Address A15-8
Address A15-8
Address A15-8
Figure 8-3: Three Cycles Instruction Timing
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Publication Release Date: December 14, 2007
Revision A2.0