Lucent Technologies MN10285K Laptop User Manual


 
Pulse Width Modulator
Block Diagram
Panasonic Semiconductor Development Company MN102H75K/F75K/85K/F85K LSI User Manual
250
Panasonic
Not using internal pullup func-
tion,Figuer10-2 connect the
external pullup registance
10.2 Block Diagram
10.3 PWM Data Registers
All registers in PWM function cannot be written by byte (be word only). Read by
byte is possible.
Bits 7 to 0 of each of the seven PWM data registers (PWM0 to PWM6) hold the
8-bit pulsewidth modulated data to be written to the PWMs. The registers reset to
0, and they set to 1 when PWM output is high.
PWM0–PWM6: PWMn Data Registers x’007E70’–x’007E7C’
Note: With a 4-MHz oscillator:
f
PWM
= f
SYSCLK
/16
Output pulse cycle = 2
8
/f
PWM
= 341.3 µs
Minimum pulse width = 1/f
PWM
= 1.33 µs
t
LOW
= (PWMn + 1) × 0.67 µs
Figure 10-2 PWM Block Diagram
Bit:76543210
PWMn7 PWMn6 PWMn5 PWMn4 PWMn3 PWMn2 PWMn1 PWMn0
Reset:00000000
R/W:RRRRRRRR
MUX
432
PnCNT
PWMn
(P15 - P17,
P20 - P23)
DAC output
I/O control
f
PWM
MSB
765 10
PWM0 - PWM6
x'007E70' - x'007E7C'
PWM (8-bit)
8
Port
PnDIR
Data bus
PnPUP