Programmable Waveform Generation Mode - Renesas M16C Series Hardware Manual

R8C/11 Group

12.3.2 Programmable Waveform Generation Mode

In this mode, an signal output from the TZ
the values in the TZPR register and TZSC register are counted alternately (see "Table 12.10 Program-
mable Waveform Generation Mode Specifications"). A counting starts by counting the value set in the
TZPR register. Figure 12.23 shows TYZMR and PUM registers in this mode. The Timer Z operates in
the same way as the Timer Y in this mode. See Figure 12.17 (Timer Y operation example in program-
mable waveform generation mode ).
Table 12.10 Programmable Waveform Generation Mode Specifications
Item
Count source
Count operation
Output waveform width
and period
Count start condition
Count stop condition
Interrupt request generation timing In half of count source, after Timer Z underflows during secondary period (at the same
TZ pin function
OUT
_____
INT0 pin functions
Read from timer
Write to timer
Select function
NOTES:
1. Even when counting the secondary period, read out the TZPR register.
2. The set value in the TZPR register and TZSC register are made effective by writing a value to the TZPR register. The
set values are reflected to the waveform output beginning with the next primary period after writing to the Timer Z
primary register.
3. The TZOCNTbit is enabled in the following timings
• When count starts
• When Timer Z interrupt request is generated
Therefore, pulse is output from the next primary period depending on the setting value of the TZOCNT bit.
Rev.1.20 Jan 27, 2006
REJ09B0062-0120
f , f , f , Timer Y underflow
1 2 8
• Down-count
• When the timer underflows, it reloads the contents of primary reload register and sec-
ondary reload register alternately before continuing counting.
Primary period : (n+1)(m+1)/f
Secondary period : (n+1)(p+1)/f
: (n+1){(m+1)+(p+1)}/f
Period
f : Count source frequency
i
n: Set value in PREZ register, m: Set value in TZPR register, p: Set value in TZSC register
Write "1" (count start) to the TZS bit in the TYZMR register
Write "0" (count stop) to the TZS bit in the TYZMR register
time as the TZout output change) [Timer Z interrupt].
Pulse output
Use timer mode when using this pin as a programmable I/O port.
Programmable I/O port, or INT0 interrupt input
Count value can be read out by reading TZPR register.
Same applies to PREZ register
Value written to TZPR register is written to reload register only.
Same applies to TZSC register and PREZ register
• Output level latch select function
The output level during primary and secondary periods is selected by the TZOPL bit.
• Programmable waveform generation output switching function
The output from TZ
the TZOCNT bit in the TYZOC register to "0". A value in the P3_1 bit is output from the
TZ by setting to "1"
OUT
page 93 of 204
pin is inverted each time the counter underflows, while
OUT
Specification
i
i
i
_______
(1)
.
is inverted synchronously when Timer Z underflows by setting
OUT
(3)
.
12.3 Timer (Timer Z)
(2)
.