C508_01 Datasheet, PDF (24/267 Pages) Infineon Technologies AG – 8-Bit CMOS Microcontroller

C508
Fundamental Structure
OSC
(XTAL2)
S1 S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6
P1 P2 P1 P2 P1 P2 P1 P2 P1 P2 P1 P2 P1 P2 P1 P2 P1 P2 P1 P2 P1 P2 P1 P2
ALE
Read
Opcode
S1 S2 S3
Read Next
Opcode (Discard)
S4 S5 S6
Read Next
Opcode Again
a) 1-byte, 1-Cycle Instruction, e.g. INC A
Read
Opcode
S1 S2 S3
Read 2nd
byte
S4 S5 S6
Read Next
Opcode
b) 2-byte, 1-Cycle Instruction, e.g. ADD A #Data
Read
Opcode
Read Next Opcode (Discard)
Read Next
Opcode Again
S1 S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6
c) 1-byte, 2-Cycle Instruction, e.g. INC DPTR
Read
Opcode
(MOVX)
Read Next
Opcode
(Discard)
No Fetch
No ALE
S1 S2 S3 S4 S5 S6 S1 S2 S3
ADDR
DATA
d) MOVX (1-byte, 2-Cycle)
Access of External Memory
Read Next
Opcode Again
No Fetch
S4 S5 S6
MCD04027
Figure 2-2 Fetch Execute Sequence
User’s Manual
2-6
2001-05