ICM7228_15 Datasheet, PDF (7/19 Pages) Intersil Corporation – 8-Digit, Microprocessor-Compatible, LED Display Decoder Driver

Timing Diagrams
MODE
WRITE
INPUT
DATA
t_MS
t_MH
t_WL
t_WH
t_DS
t_DH
VALID
FIGURE 1. ICM7228A/B WRITE CYCLE
ICM7228
MODE
WRITE
(D1)
CONTROL WORD
WRITE DATA
8 PULSES
TYPE OF DECODER?ID6
DECODE/NO DECODE? ID5
SHUTDOWN?ID4
DATA COMING ID7
(D8) ^{DON’T CARE}
CONTROL WORD
TYPE OF DECODER?ID6
DECODE/NO DECODE? ID5
SHUTDOWN? ID4
DATA COMING ID7
FIGURE 2. ICM7228A/B SEQUENTIAL 8-DIGIT RAM UPDATE
DIGIT
ADDRESS
DAO-DAZ
WRITE
DATA
VALID
t_AS
t_WL
t_DS
t_AH
t_WH
t_DH
VALID DATA
FIGURE 3. ICM7228C WRITE CYCLE
INTERDIGIT BLANKING
INTERNAL SIGNAL
D2
D5
D1
D7
TYPICAL DIGITS ^D8
OUTPUT PULSES _D6
D4
D3
10s (TYP)
FREE RUNNING
320s (TYP)
FREE RUNNING (PER DIGIT)
INTERDIGIT BLANKING
FIGURE 4. DISPLAY DIGITS MULTIPLEX (COMMON ANODE DISPLAY)
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