cdp1871ac Intersil Corporation, cdp1871ac Datasheet - Page 9

• Manufacturer Part Number: cdp1871ac
• Description: Cmos Keyboard Encoder
• Manufacturer: Intersil Corporation

NOTE: CS = CS1 CS2 CS3 CS4
NOTE: CS = CS1 CS2 CS3 CS4
DEPRESSED
DEBOUNCE
BUS0-BUS7
DEBOUNCE
BUS0-BUS7
CLOSURE
(NOTE)
D1-D11
CS1, CS2, CS3 = (CPU N-LINES)
CS4 (MRD) is High for CPU Input Instruction
D1-D11
(NOTE)
CS1, CS2, CS3 = (CPU N-LINES)
CS4 (MRD) is High for CPU Input Instruction
KEY
TPB
RPT
KEY
TPB
RPT
DA
CS
DA
CS
PRESENT COUNT
t
CWH
FIGURE 4. FIGURE 4. CDP1871A DYNAMIC TIMING DIAGRAM (REPEAT)
PRESENT COUNT
R
FIGURE 3. CDP1871A DYNAMIC TIMING DIAGRAM (NON-REPEAT)
t
N
DAL
C
t
CDV
X
t
CC
t
CLOSED
CWL
VALID
CLOSED
CDP1871A, CDP1871AC
t
CDH
t
DAH
t
RPL
OPEN
4-74
R
t
X
RPH
R
C
X
X
C
X
OPEN
t
CDV
VALID
NEXT COUNT
t
t
CDH
CD1
t
DAH
NEXT COUNT