C515C_9711 Datasheet, PDF (44/268 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

External Bus Interface
C515C
a)
ALE
One Machine Cycle
One Machine Cycle
S1 S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6
PSEN
(A)
RD
without
MOVX
P2
PCH
OUT
PCH
OUT
PCH
OUT
PCH
PCH
OUT
OUT
P0
INST PCL
IN OUT
INST PCL
IN OUT
INST PCL
IN OUT
INST PCL INST
IN OUT
IN
PCL OUT
valid
PCL OUT
valid
PCL OUT
valid
PCL OUT
valid
b)
One Machine Cycle
One Machine Cycle
S1 S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6
ALE
PSEN
RD
P2
PCH
OUT
PCH
OUT
DPH OUT OR
P2 OUT
P0
INST PCL
INST
IN OUT
IN
DATA
IN
PCL OUT
valid
DPL or Ri
valid
(B)
with
MOVX
PCH
OUT
PCL INST
OUT
IN
PCL OUT
valid
MCD02575
Figure 4-1
External Program Memory Execution
Semiconductor Group
4-2
1997-11-01