ST72T631K4M1 STMicroelectronics, ST72T631K4M1 Datasheet - Page 36

• Manufacturer Part Number: ST72T631K4M1
• Description: Microcontrollers (MCU) OTP EPROM 16K USB/SC
• Manufacturer: STMicroelectronics

Specifications of ST72T631K4M1

• Data Bus Width: 8 bit
• Program Memory Type: EPROM
• Program Memory Size: 16 KB
• Data Ram Size: 512 B
• Interface Type: I2C, SCI, USB
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 19
• Number Of Timers: 2
• Operating Supply Voltage: 4 V to 5.5 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: SO-34
• Minimum Operating Temperature: 0 C
• On-chip Adc: 8 bit
• Lead Free Status / Rohs Status: No

ST7263
5.4 16-BIT TIMER
5.4.1 Introduction
The timer consists of a 16-bit free-running counter
driven by a programmable prescaler.
It may be used for a variety of purposes, including
measuring the pulse lengths of up to two input sig-
nals ( input capture ) or generating up to two output
waveforms ( output compare and PWM ).
Pulse lengths and waveform periods can be mod-
ulated from a few microseconds to several milli-
seconds using the timer prescaler and the CPU
clock prescaler.
Some ST7 devices have two on-chip 16-bit timers.
They are completely independent, and do not
share any resources. They are synchronized after
a MCU reset as long as the timer clock frequen-
cies are not modified.
This description covers one or two 16-bit timers. In
ST7 devices with two timers, register names are
prefixed with TA (Timer A) or TB (Timer B).
5.4.2 Main Features
The Block Diagram is shown in
*Note: Some timer pins may not be available (not
bonded) in some ST7 devices. Refer to the device
pin out description.
When reading an input signal on a non-bonded
pin, the value will always be ‘1’.
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Programmable prescaler: f
Overflow status flag and maskable interrupt
External clock input (must be at least 4 times
slower than the CPU clock speed) with the choice
of active edge
Output compare functions with:
– 2 dedicated 16-bit registers
– 2 dedicated programmable signals
– 2 dedicated status flags
– 1 dedicated maskable interrupt
Input capture functions with:
– 2 dedicated 16-bit registers
– 2 dedicated active edge selection signals
– 2 dedicated status flags
– 1 dedicated maskable interrupt
Pulse Width Modulation mode (PWM)
One Pulse mode
5 alternate functions on I/O ports (ICAP1, ICAP2,
OCMP1, OCMP2, EXTCLK)*
CPU
divided by 2, 4 or 8.
Figure
1.
5.4.3 Functional Description
5.4.3.1 Counter
The main block of the Programmable Timer is a
16-bit free running upcounter and its associated
16-bit registers. The 16-bit registers are made up
of two 8-bit registers called high & low.
Counter Register (CR):
Alternate Counter Register (ACR)
These two read-only 16-bit registers contain the
same value but with the difference that reading the
ACLR register does not clear the TOF bit (Timer
overflow flag), located in the Status register (SR).
(See note at the end of paragraph titled 16-bit read
sequence).
Writing in the CLR register or ACLR register resets
the free running counter to the FFFCh value.
Both counters have a reset value of FFFCh (this is
the only value which is reloaded in the 16-bit tim-
er). The reset value of both counters is also
FFFCh in One Pulse mode and PWM mode.
The timer clock depends on the clock control bits
of the CR2 register, as illustrated in
value in the counter register repeats every
131.072, 262.144 or 524.288 CPU clock cycles
depending on the CC[1:0] bits.
The timer frequency can be f
or an external frequency.
– Counter High Register (CHR) is the most sig-
– Counter Low Register (CLR) is the least sig-
– Alternate Counter High Register (ACHR) is the
– Alternate Counter Low Register (ACLR) is the
nificant byte (MS Byte).
nificant byte (LS Byte).
most significant byte (MS Byte).
least significant byte (LS Byte).
CPU
/2, f
CPU
Table
/4, f
1. The
CPU
/8