Fujitsu MB89950/950A Pager User Manual


 
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CHAPTER 8 PULSE WIDTH COUNT TIMER (PWC)
8.2 Block Diagram of Pulse Width Count Timer
The pulse width count timer consists of the following nine blocks:
Count clock selector
8-bit down counter
Input pulse edge detector
Noise filter circuit
Noise filter clock selector
PWC reload buffer register (RLBR)
PWC pulse width control register 1 (PCR1)
PWC pulse width control register 2 (PCR2)
Noise filter control register (NCCR)
Block diagram of pulse width count timer
Figure 8.2-1 Block diagram of pulse width count timer
FC RM TO C1 C0 W1 W0
Pin
PCR1
PCR2
IRQ3
P42/PWC/INT1
RLBR
X1
X4
X32
EN IE ——UF IR BF
1 t
inst
Internal data bus
8-bit down counter
Input pulse edge
detector
Count
clock
selector
To PWM timer
Noise filter
——————NCS1 NCS0
filter
From
timebase
timer
circuit
clock
selector
NCCR
Noise
tinst: Instruction cycle