M34282E2GP MITSUBISHI [Mitsubishi Electric Semiconductor], M34282E2GP Datasheet - Page 10

• Manufacturer Part Number: M34282E2GP
• Description: SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

TIMERS
The 4282 Group has the programmable timer.
• Programmable timer
Fig. 12 Auto-reload function
The 4282 Group timer consists of the following circuit.
• Timer 1 : 8-bit programmable timer
• Timer 2 : 8-bit programmable timer
These timers can be controlled with the timer control registers
V1 and V2.
Each timer function is described below.
Table 3 Function related timer
10
Timer 1
Timer 2
14-bit timer
The programmable timer has a reload register and enables
the frequency dividing ratio to be set. It is decremented from a
setting value n. When it underflows (count to n + 1), a timer 1
underflow flag is set to “1,” new data is loaded from the reload
register, and count continues (auto-reload function).
Timer 1 underflow flag “1”
Circuit
8-bit programmable
binary down counter
8-bit programmable
binary down counter
14-bit fixed frequency
Structure
FF
00
“0”
16
16
n
n: Counter initial value
Count starts
• Carrier wave output (CARRY)
• Bit 5 of watchdog timer
• f(X
• f(X
• Instruction clock
IN
IN
)
)/2
n+1 count
Count source
1st underflow
MITSUBISHI
ELECTRIC
Reload
1 to 256
1 to 256
16384
dividing ratio
Frequency
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
n+1 count
2nd underflow
A skip instruction is executed
• Carrier wave output control
• Carrier wave output
• Watchdog timer
• Timer 1 count source
MITSUBISHI MICROCOMPUTERS
Use of output signal
Reload
4282 Group
Time
register
Control
V1
V2