ST52T440F3M6 STMicroelectronics, ST52T440F3M6 Datasheet - Page 56

• Manufacturer Part Number: ST52T440F3M6
• Description: MCU 8-Bit ST52 CISC 8KB EPROM 5V 20-Pin SO
• Manufacturer: STMicroelectronics

Specifications of ST52T440F3M6

• Package: 20SO
• Family Name: ST52
• Maximum Speed: 20 MHz
• Ram Size: 256 Byte
• Program Memory Size: 8 KB
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Program Memory Type: EPROM
• Number Of Programmable I/os: 13
• On-chip Adc: 6-chx12-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 1

ST52T400/T440/E440/T441
9 PWM/TIMER
ST52x400/440/441 on-chip PWM/TIMER periph-
erals consist of an 8-bit counter with a 16-bit pro-
grammable prescaler that provide a maximum
count of 2
The TIMER has two different working modes:
The Timer has an Autoreload Function in PWM
Mode. Its output TOUT is available, with its com-
plementary signal TOUTN on external pins by set-
ting PA6 and PA2 bits of REG_CONF4 and
REG_CONF12 (see tables - Port A - REG_CONF
4 and - Port A - REG_CONF 12).
The TIMER can also use an external START/
STOP signal (Input capture), an external RESET
and external CLOCK signals: PA4/TSTRT, PA6/
TRES and PA5/TCLK pins. To use TSTRT, TRES,
TCLK external signals the related pins PA4, PA6
and PA5 must be configured in Input Mode by set-
ting registers REG_CONF4 and REG_CONF12
(see table - Port A - REG_CONF 4 and - Port A -
REG_CONF 12).
The content of the 8-bit counter of the TIMER is
incremented on the Rising Edge of the 16-bit pres-
caler output (PRESCOUT) and it can be read at
any instant of the counting phase, which is then
saved in a RAM memory location. The PWM/
Timer Counter value can be read from the Input
Register PWM_COUNT (Input Registers 18, see
Table 2.1). The PWM/Timer Status can be read
from the Input Register PWM_STATUS (Input
Registers 19. See Table 2.1). This register indi-
cates if the TIMER is in START/STOP (bit 1) and
in SET/RESET bit(0).
Figure 9.1 Timer Peripheral Block Diagram
56/94
Timer Mode
PWM (Pulse Width Modulation) Mode that can
be selected by setting register REG_CONF5[7]
bit TMODE.
24
(Figure 9.1).
C LK M
BIT0
BIT0
BIT1
BIT1
BIT2
BIT2
BIT3
BIT3
8-BITCO UN TER
16-BITPR ESCA LER
17-1M UL TIPLEXER
BIT4
BIT4
TMR CLK
BIT5
BIT5
9.1 Timer Mode
Timer Mode is selected by setting the TxMODE bit
of REG_CONF5[7].
The TIMER can receive three signals as inputs:
Timer Clock (TCLK), Timer Reset (TRES) and
Timer Start (TSTRT) (Figure 9.1). Each of these
signals can be generated internally or externally
by
REG_CONF7 register as illustrated in Table 9.3.
TMRCLK is the Prescaler output, which incre-
ments the Counter value on the rising edge. TMR-
CLK is obtained from the internal clock signal
(CLKM) or from the external signal provided on
the PA5/TCLK pin.
NOTE: The external clock signal, applied on
TCLK pin, must have a frequency, which is at least
two times smaller than the internal master clock.
The prescaler output can be selected by setting
PRESC bits of REG_CONF6 register (Table 9.2).
TRES resets the content of the TIMER 8-bit
counter to zero. It is generated internally by set-
ting the TIRST bit of REG_CONF5(Table 9.1).
TSTRT signal starts and stops the Timer counting
only if the peripheral is configured in Timer mode.
It is generated internally by setting the TSTR bit of
REG_CONF5(Table 9.1).
TIMER START/STOP can be provided externally
from the TSTRT pin (Input Capture). In this case,
TSTRT signal allows the ICU to work in two differ-
ent modes by setting the TESTR configuration bit
of REG_CONF5 register.
LEVEL: When the TSTRT signal is high the Timer
starts counting. When the TSTRT is low the count-
ing stops and the current value is stored in the
PWMCOUNT Input Register.
BIT6
setting
BIT7
BIT14
TSTR,
BIT15
PRESCx
TRST,
TxR ES
TxSTRT
TCLK
bits
of