ST72C254G2M6 STMicroelectronics, ST72C254G2M6 Datasheet - Page 48
![IC MCU 8BIT 8K FLASH SOIC-28](/photos/6/56/65690/stmicroelectronics-28-soic_sml.jpg)
ST72C254G2M6
Manufacturer Part Number
ST72C254G2M6
Description
IC MCU 8BIT 8K FLASH SOIC-28
Manufacturer
STMicroelectronics
Series
ST7r
Datasheets
1.INDART-ST72C254.pdf
(3 pages)
2.ST72C104G1M6.pdf
(141 pages)
3.ST72C215G2M6.pdf
(140 pages)
Specifications of ST72C254G2M6
Core Processor
ST7
Core Size
8-Bit
Speed
16MHz
Connectivity
I²C, SPI
Peripherals
LVD, POR, PWM, WDT
Number Of I /o
22
Program Memory Size
8KB (8K x 8)
Program Memory Type
FLASH
Ram Size
256 x 8
Voltage - Supply (vcc/vdd)
3.2 V ~ 5.5 V
Data Converters
A/D 6x8b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
28-SOIC (7.5mm Width)
Controller Family/series
ST7
No. Of I/o's
22
Ram Memory Size
256Byte
Cpu Speed
8MHz
No. Of Timers
2
Rohs Compliant
Yes
Processor Series
ST72C2x
Core
ST7
Data Bus Width
8 bit
Data Ram Size
256 B
Interface Type
I2C, SPI
Maximum Clock Frequency
16 MHz
Number Of Programmable I/os
22
Number Of Timers
3 bit
Operating Supply Voltage
3.2 V to 5.5 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Development Tools By Supplier
ST7MDT1-DVP2/US
Minimum Operating Temperature
- 40 C
On-chip Adc
8 bit
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Lead Free Status / Rohs Status
In Transition
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ST72C254G2M6
Manufacturer:
ST
Quantity:
20 000
ST72104Gx, ST72215Gx, ST72216Gx, ST72254Gx
16-BIT TIMER (Cont’d)
11.2.3.4 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:
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 OC
Timing resolution is one count of the free running
counter: (
Procedure:
To use the output compare function, select the fol-
lowing in the CR2 register:
– Set the OCiE bit if an output is needed then the
– Select the timer clock (CC[1:0]) (see
And select the following in the CR1 register:
– Select the OLVLi bit to applied to the OCMPi pins
– Set the OCIE bit to generate an interrupt if it is
When a match is found between OCRi register
and CR register:
– OCFi bit is set.
48/141
OCMPi pin is dedicated to the output compare i
signal.
after the match occurs.
needed.
– Assigns pins with a programmable value if the
– Sets a flag in the status register
– Generates an interrupt if enabled
OCiR
OCiE bit is set
f
CPU/
CC[1:0]
i
R value to 8000h.
MS Byte
OCiHR
).
LS Byte
OCiLR
Table
1).
– The OCMPi pin takes OLVLi bit value (OCMPi
– A timer interrupt is generated if the OCIE bit is
The OC
ing application can be calculated using the follow-
ing formula:
Where:
∆
f
PRESC
If the timer clock is an external clock, the formula
is:
Where:
∆
f
Clearing the output compare interrupt request (i.e.
clearing the OCFi bit) is done by:
1. Reading the SR register while the OCFi bit is
2. An access (read or write) to the OCiLR register.
The following procedure is recommended to pre-
vent the OCFi bit from being set between the time
it is read and the write to the OC
– Write to the OCiHR register (further compares
– Read the SR register (first step of the clearance
– Write to the OCiLR register (enables the output
CPU
EXT
t
t
pin latch is forced low during reset).
set in the CR1 register and the I bit is cleared in
the CC register (CC).
are inhibited).
of the OCFi bit, which may be already set).
compare function and clears the OCFi bit).
set.
i
R register value required for a specific tim-
= Output compare period (in seconds)
= CPU clock frequency (in hertz)
= Timer prescaler factor (2, 4 or 8 de-
= Output compare period (in seconds)
= External timer clock frequency (in hertz)
pending on CC[1:0] bits, see
∆
∆
OCiR =
OCiR =
∆t
∆t
*
PRESC
f
EXT
*
f
CPU
i
R register:
Table
1)