参数资料
型号: ST72324K2T6/XXX
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP32
封装: TQFP-32
文件页数: 124/161页
文件大小: 2070K
代理商: ST72324K2T6/XXX
ST72324
65/161
16-BIT TIMER (Cont’d)
10.3.3.4 Output Compare
In this section, the index,
i, may be 1 or 2 because
there are 2 output compare functions in the 16-bit
timer.
This function can be used to control an output
waveform or indicate when a period of time has
elapsed.
When a match is found between the Output Com-
pare register and the free running counter, the out-
put compare function:
– Assigns pins with a programmable value if the
OC
iE bit is set
– Sets a flag in the status register
– Generates an interrupt if enabled
Two 16-bit registers Output Compare Register 1
(OC1R) and Output Compare Register 2 (OC2R)
contain the value to be compared to the counter
register each timer clock cycle.
These registers are readable and writable and are
not affected by the timer hardware. A reset event
changes the OCiR value to 8000h.
Timing resolution is one count of the free running
counter: (
fCPU/CC[1:0]).
Procedure:
To use the output compare function, select the fol-
lowing in the CR2 register:
– Set the OC
iE bit if an output is needed then the
OCMP
i pin is dedicated to the output compare i
signal.
– Select the timer clock (CC[1:0]) (see Table 15
And select the following in the CR1 register:
– Select the OLVL
i bit to applied to the OCMPi pins
after the match occurs.
– Set the OCIE bit to generate an interrupt if it is
needed.
When a match is found between OCRi register
and CR register:
– OCF
i bit is set.
– The OCMP
i pin takes OLVLi bit value (OCMPi
pin latch is forced low during reset).
– A timer interrupt is generated if the OCIE bit is
set in the CR1 register and the I bit is cleared in
the CC register (CC).
The OCiR register value required for a specific tim-
ing application can be calculated using the follow-
ing formula:
Where:
t
= Output compare period (in seconds)
fCPU
= CPU clock frequency (in hertz)
PRESC = Timer prescaler factor (2, 4 or 8 de-
pending on CC[1:0] bits, see Table 15
If the timer clock is an external clock, the formula
is:
Where:
t
= Output compare period (in seconds)
fEXT
= External timer clock frequency (in hertz)
Clearing the output compare interrupt request (i.e.
clearing the OCF
i bit) is done by:
1. Reading the SR register while the OCF
i bit is
set.
2. An access (read or write) to the OC
iLR register.
The following procedure is recommended to pre-
vent the OCF
i bit from being set between the time
it is read and the write to the OCiR register:
– Write to the OC
iHR register (further compares
are inhibited).
– Read the SR register (first step of the clearance
of the OCF
i bit, which may be already set).
– Write to the OC
iLR register (enables the output
compare function and clears the OCF
i bit).
MS Byte
LS Byte
OC
iROCiHR
OC
iLR
OCiR =
t * fCPU
PRESC
OCiR = t
* fEXT
相关PDF资料
PDF描述
ST72324J4TC/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP44
ST72324K4T3/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP32
ST72324K6T3/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP32
ST72324K2B7/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP32
ST72324K2B3/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP32
相关代理商/技术参数
参数描述
ST72324K4 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC, 4 TIMERS, SPI, SCI INTERFACE
ST72324K4B 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC, 4 TIMERS, SPI, SCI INTERFACE
ST72324K4B6 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT MCU WITH NESTED INTERRUPTS. FLASH. 10-BIT ADC. 4 TIMERS. SPI. SCI INTERFACE
ST72324K4T 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC, 4 TIMERS, SPI, SCI INTERFACE
ST72324K6 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC, 4 TIMERS, SPI, SCI INTERFACE