M16C1N Datasheet, PDF (107/238 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/10 SERIES

M16C/1N Group
12. Timers
12.4.1 Timer Mode
In this mode, the timer counts an internally generated count source or Timer Y underflow. (See Table
12.10) The Timer Z secondary is unused in this mode. Figure 12.25 shows the Timer Y, Z mode
register and Timer Y, Z waveform output control register in timer mode.
Table 12.10 Specifications of timer mode
Item
Specification
Count source
f1, f8, Timer Y underflow, fC32
Count operation
• Down count
• When the timer underflows, it reloads the reload register contents before continuing
counting (When the Timer Z underflows, the contents of the Timer Z primary reload
register is reloaded.)
• When a counting stops, the timer reloads the content of the reload register before
Divide ratio
Count start condition
stopping counting.
1
(n+1) X (m+1)
n: Set value of Prescaler Z, m: Set value of Timer Z primary
Count start flag is set (=1)
Count stop condition
Count start flag is reset (=0) (Note 1)
Interrupt request generation timing When Timer Z underflows
TYOUT pin function
Programmable I/O port
INT0 pin function
Programmable I/O port, or external interrupt input pin
Read from timer
Count value can be read out by reading Timer Z primary register.
Same applies to Prescaler Z register.
Write to timer
When a value is written to Timer Z Primary register, it is written to both reload register
and counter or written to only reload register. Selected by software.
Same applies to Prescaler Z register.
Select function
• Timer Z write control function (Note 2)
When a value is written to Timer Z Primary register, it can be selected that the value is
written to both reload register and counter or written to only reload register.
Same applies to Prescaler Z register.
Note 1: When the count is stopped, the Timer Z interrupt request bit becomes "1" and an interrupt may occur. Thus,
interrupts must be disabled before the count is stopped. Furthermore, set the Timer Z interrupt request bit to "0"
before starting counting again.
Note 2: If writing to the Timer Z or prescaler Z under the following conditions being filled at the same time the Timer Z
interrupt request bit becomes "1" and an interrupt occurs.
<Conditions>
• Timer Z write control bit (bit 6 at address 008016) is "0" (write to timer and reload register simultaneously)
• Timer Z count start flag (bit 7 at address 008016) is "1" (count start)
To write to the Timer Z or prescaler Z in the above state, disable interrupts before writing.
Rev.1.00 Oct 20, 2004 page 95 of 222
REJ09B0007-0100Z