R8C/10 Group
Rev.1.20 Jan 27, 2006 page 68 of 180
REJ09B0019-0120
12.2.1 Timer Mode
In this mode, the timer counts an internally generated count source (see “Table 12.7 Timer Mode
Specifications”). An external signal input to the CNTR1 pin can be counted. The TYSC register is
unused in timer mode. Figure 12.15 shows the TYZMR and PUM registers in timer mode.
Item Specification
Count source f1, f8, fRING, external signal fed to CNTR1 pin
Count operation • Down-count
• When the timer underflows, it reloads the reload register contents before continuing
counting (When the Timer Y underflows, the contents of the Timer Y primary reload
register is reloaded.)
Divide ratio 1/(n+1)(m+1) n: set value in PREY register, m: set value in TYPR register
Count start condition Write “1” (count start) to TYS bit in TYZMR register
Count stop condition Write “0” (count stop) to TYS bit in TYZMR register
Interrupt request • When Timer Y underflows [Timer Y interrupt]
generation timing
INT2/CNTR
1 pin function
_______
Programmable I/O port, count source input or INT2 interrupt input
• When the TYCK1 to TYCK0 bits in the TCSS register are set to “00b”, “01b” or “10b”
_______
(Timer Y count source is f1, f8 or fRING), programmable I/O port or INT2 interrupt input
• When the TYCK1 to TYCK0 bits are set to “11b” (Timer Y count source is CNTR
1
_______
input), count source input (INT2 interrupt input)
Read from timer Count value can be read out by reading TYPR register.
Same applies to PREY register.
Write to timer
(1)
Value written to TYPR register is written to both reload register and counter or written to
only reload register. Selected by program.
Same applies to PREY register.
Select function • Event counter function
When setting TYCK1 to TYCK0 bits to “112”, an external signal fed to CNTR1 pin is
counted.
_______
• INT2/CNTR1 switching bit
Active edge of count source is selected by R1EDG bit.
NOTES:
1. The IR bit in the TYIC register is set to "1" (interrupt requested) if you write to the TYPR or PREY register while both
of the following conditions are met.
Conditions:
• TYWC bit in TYZMR register is "0" (write to reload register and counter simultaneously)
• TYS bit is "1" (count start)
To write to the TYPR or PREY register in the above state, disable interrupts before writing.
Table 12.7 Timer Mode Specifications
12.2 Timer (Timer Y)
(120 páginas)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comentários a estes Manuais