CDP1802A, CDP1802AC, CDP1802BC
Machine Cycle Timing Waveforms (Propagation Delays Not Shown) (Continued)
0 1 2 3 4 56 7 0 12 3 4 5 6 7 01 2 34 5 6 7
CLOCK
TPA
TPB
MACHINE
CYCLE
INSTRUCTION
CYCLE n
FETCH (S0)
CYCLE (n+1)
EXECUTE (S1)
CYCLE (n+2)
DMA (S2)
DMA-IN
MRD
MWR
MEMORY
OUTPUT
DATA BUS
(NOTE 1)
MEMORY READ CYCLE
VALID OUTPUT
MEMORY READ, WRITE
OR NON-MEMORY CYCLE
VALID DATA FROM INPUT DEVICE
MEMORY WRITE CYCLE
NOTE 1
USER GENERATED SIGNAL
“DON’T CARE” OR INTERNAL DELAYS
HIGH IMPEDANCE STATE
FIGURE 12. DMA IN CYCLE TIMING WAVEFORMS
01234567012345670123456
CLOCK
TPA
TPB
MACHINE
CYCLE
CYCLE n
CYCLE (n + 1)
CYCLE (n + 2)
INSTRUCTION
FETCH (S0)
EXECUTE (S1)
DMA (S2)
DMA OUT
(NOTE 1)
MRD
MWR
MEMORY
OUTPUT
DATA
STROBE
(S2 • TPB)
(NOTE 1)
MEMORY READ CYCLE
NOTE 1
USER GENERATED SIGNAL
VALID OUTPUT
VALID DATA FROM MEMORY
MEMORY READ, WRITE
OR NON-MEMORY CYCLE
“DON’T CARE” OR INTERNAL DELAYS
MEMORY READ CYCLE
HIGH IMPEDANCE STATE
FIGURE 13. DMA OUT CYCLE TIMING WAVEFORMS
3-16