M16C1N Datasheet, PDF (83/238 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/10 SERIES

M16C/1N Group
12. Timers
12.1 Timer 1
Timer 1 is an 8-bit timer with an 8-bit prescaler. Figure 12.1 shows the block diagram of Timer 1. The timer
constantly counts an internally generated count source (clock source). The count source after reset is set
to f1. The timer cannot stop counting. Table 12.2 shows the specifications of Timer 1 and Figure 12.2
shows Timer 1 related registers.
Clock source
selection
f1
f8
f32
fC32
Peripheral data bus
Reload register (8)
Reload register (8)
fP1
Counter (8)
Prescaler 1 (address 008816)
Counter (8)
Timer 1 (address 008916)
Timer 1 interrupt
request bit
Figure 12.1 Block diagram of Timer 1
Table 12.2 Specifications of Timer 1 (Timer mode)
Item
Specification
Count source
f1, f8, f32, fC32
Count operation
• Down count
• When the timer underflows, it reloads the reload register contents before continuing
Divide ratio
counting
1
(n+1) X (m+1)
n: Set value of Prescaler 1, m: Set value of Timer 1
Count start condition
After reset
Count stop condition
Disable to stop counting
Interrupt request generation timing When Timer 1 underflows
Read from timer
Count value can be read out by reading Timer 1 register.
Same applies to Prescaler 1 register.
Write to timer
When a value is written to Timer 1 register, it is written to both reload register and
counter.
Same applies to Prescaler 1 register.
Rev.1.00 Oct 20, 2004 page 71 of 222
REJ09B0007-0100Z