ST10F269-T3 STMicroelectronics, ST10F269-T3 Datasheet - Page 51

• Manufacturer Part Number: ST10F269-T3
• Manufacturer: STMicroelectronics

Specifications of ST10F269-T3

• Cpu Family: ST10
• Device Core Size: 16b
• Frequency (max): 32MHz
• Interface Type: ASC/I2C/SSC
• Program Memory Type: Flash
• Program Memory Size: 256KB
• Total Internal Ram Size: 12KB
• # I/os (max): 111
• Number Of Timers - General Purpose: 4
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4.5V
• On-chip Adc: 16-chx10-bit
• Instruction Set Architecture: CISC/RISC
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 144
• Package Type: TQFP
• Lead Free Status / Rohs Status: Supplier Unconfirmed

10 - GENERAL PURPOSE TIMER UNIT
The GPT unit is a flexible multifunctional timer/
counter structure which is used for time related
tasks such as event timing and counting, pulse
width and duty cycle measurements, pulse
generation, or pulse multiplication. The GPT unit
contains five 16-bit timers organized into two
separate modules GPT1 and GPT2. Each timer in
each module may operate independently in
several different modes, or may be concatenated
with another timer of the same module.
10.1 - GPT1
Each of the three timers T2, T3, T4 of the GPT1
module can be configured individually for one of
four basic modes of operation: timer, gated timer,
counter mode and incremental interface
mode.
In timer mode, the input clock for a timer is derived
from the CPU clock, divided by a programmable
prescaler.
In counter mode, the timer is clocked in reference
to external events.
Pulse width or duty cycle measurement is
supported in gated timer mode where the
operation of a timer is controlled by the ‘gate’ level
on an external input pin. For these purposes, each
timer has one associated port pin (TxIN) which
serves as gate or clock input.
Table 11 lists the timer input frequencies,
resolution and periods for each pre-scaler option
at 32MHz CPU clock. This also applies to the
Gated Timer Mode of T3 and to the auxiliary
timers T2 and T4 in Timer and Gated Timer Mode.
The count direction (up/down) for each timer is
programmable by software or may be altered
Table 11 : GPT1 Timer Input Frequencies, Resolution and Periods
Pre-scaler factor
Input Freq
Resolution
Period
maximum
f
CPU
= 32MHz
16.4ms
250ns
4MHz
000b
8
32.8ms
500ns
2MHz
001b
16
65.5ms
1MHz
010b
1µs
32
Timer Input Selection T2I / T3I / T4I
500KHz
131ms
011b
2µs
64
dynamically by an external signal on a port pin
(TxEUD).
In Incremental Interface Mode, the GPT1 timers
(T2, T3, T4) can be directly connected to the
incremental position sensor signals A and B by
their respective inputs TxIN and TxEUD.
Direction and count signals are internally derived
from these two input signals so that the contents
of the respective timer Tx corresponds to the
sensor position. The third position sensor signal
TOP0 can be connected to an interrupt input.
Timer T3 has output toggle latches (TxOTL) which
changes state on each timer over flow / underflow.
The state of this latch may be output on port pins
(TxOUT) for time out monitoring of external
hardware components, or may be used internally
to clock timers T2 and T4 for high resolution of
long duration measurements.
In addition to their basic operating modes, timers
T2 and T4 may be configured as reload or capture
registers for timer T3. When used as capture or
reload registers, timers T2 and T4 are stopped.
The contents of timer T3 is captured into T2 or T4
in response to a signal at their associated input
pins (TxIN).
Timer T3 is reloaded with the contents of T2 or T4
triggered either by an external signal or by a
selectable state transition of its toggle latch
T3OTL. When both T2 and T4 are configured to
alternately reload T3 on opposite state transitions
of T3OTL with the low and high times of a PWM
signal, this signal can be constantly generated
without software intervention.
262.1ms
250KHz
100b
128
4µs
524.3ms
125KHz
101b
256
8µs
62.5KHz
1.05s
110b
16µs
512
ST10F269-T3
31.125KHz
111b
1024
32µs
2.1s
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