UPD784915B Datasheet, PDF (37/86 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784915B, 784916B
(7) Up/down counter unit
The up/down counter unit is a counter that realizes a linear time counter.
This unit consists of an up/down counter (UDC) and a compare register (UDCC).
The up/down counter counts up the rising edges of PBCTL and counts down the falling edges of PBCTL. When
the value of the up/down counter coincides with the value of the compare register, or when the counter underflows,
an interrupt request is generated.
Figure 3-14. Block Diagram of Up/Down Counter Unit
PTO10
PTO11
PBCTL
SELUD
P77
EDVC output
UP/DOWN
UDC
UDCC
INTUDC
(8) PWM output unit
The PWM output unit has three 16-bit accuracy output lines (PWM0, PWM1, and PWM5) and 8-bit accuracy
output lines (PWM2 to PWM4). The carrier frequency of all the output lines is 62.5 kHz (fCLK = 8 MHz).
PWM0 and PWM1 can be used to control the drum motor and capstan motor.
Figure 3-15. Block Diagram of 16-Bit PWM Output Unit
Internal bus
(n = 0, 1, 5)
PWMn
15
16
87
8
Reload
8
0
PWMC0
8
Reload _{Reload control}
To selector
16 MHz
8-bit down counter
1/256
PWM pulse
generation circuit
8-bit counter
Output control
circuit
PWMn
RESET
37