UPSD3254 STMICROELECTRONICS [STMicroelectronics], UPSD3254 Datasheet - Page 58

• Manufacturer Part Number: UPSD3254
• Description: Flash Programmable System Devices with 8032 Microcontroller Core
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

UPSD3254A, UPSD3254BV, UPSD3253B, UPSD3253BV
Table 40. Timer/Counter 2 Control Register (T2CON)
Table 41. Description of the T2CON Bits
Note: 1. The RCLK1 and TCLK1 Bits in the PCON Register control UART 2, and have the same function as RCLK and TCLK.
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TF2
Bit
7
7
6
5
4
3
2
1
0
RCLK
Symbol
TCLK
CP/RL2
EXEN2
EXF2
EXF2
C/T2
TR2
TF2
6
(1)
(1)
Timer 2 overflow flag. Set by a Timer 2 overflow, and must be cleared by software. TF2
will not be set when either (RCLK, RCLK1)=1 or (TCLK, TCLK)=1
Timer 2 external flag set when either a capture or reload is caused by a negative
transition on T2EX and EXEN2=1. When Timer 2 Interrupt is enabled, EXF2=1 will
cause the CPU to vector to the Timer 2 Interrupt routine. EXF2 must be cleared by
software
Receive clock flag (UART 1). When set, causes the serial port to use Timer 2 overflow
pulses for its receive clock in Modes 1 and 3. TCLK=0 causes Timer 1 overflow to be
used for the receive clock
Transmit clock flag (UART 1). When set, causes the serial port to use Timer 2 overflow
pulses for its transmit clock in Modes 1 and 3. TCLK=0 causes Timer 1 overflow to be
used for the transmit clock
Timer 2 external enable flag. When set, allows a capture or reload to occur as a result of
a negative transition on T2EX if Timer 2 is not being used to clock the serial port.
EXEN2=0 causes Time 2 to ignore events at T2EX
Start/stop control for Timer 2. A logic 1 starts the timer
Timer or Counter select for Timer 2. Cleared for timer operation (input from internal
system clock, t
Capture/reload flag. When set, capture will occur on negative transition of T2EX if
EXEN2=1. When cleared, auto-reload will occur either with TImer 2 overflows, or
negative transitions of T2EX when EXEN2=1. When either (RCLK, RCLK1)=1 or (TCLK,
TCLK)=1, this bit is ignored, and timer is forced to auto-reload on Timer 2 overflow
RCLK
5
CPU
TCLK
); set for external event counter operation (negative edge triggered)
4
EXEN2
3
Function
TR2
2
C/T2
1
CP/RL2
0