AT89C5131A-L Atmel Corporation, AT89C5131A-L Datasheet - Page 73

• Manufacturer Part Number: AT89C5131A-L
• Manufacturer: Atmel Corporation

Specifications of AT89C5131A-L

• Flash (kbytes): 32 Kbytes
• Max. Operating Frequency: 48 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 1.25
• Eeprom (bytes): 1024
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 3.6
• Timers: 4
• Isp: UART/USB
• Watchdog: Yes

4338F–USB–08/07
BRL - Baud Rate Reload Register for the internal baud rate generator, UART (9Ah)
Reset Value = 0000 0000b
Table 57. T2CON Register
T2CON - Timer 2 Control Register (C8h)
Reset Value = 0000 0000b
Bit addressable
Number
TF2
Bit
7
7
6
5
4
3
2
1
0
7
–
Mnemonic
CP/RL2#
EXEN2
EXF2
C/T2#
RCLK
EXF2
TCLK
TR2
Bit
TF2
6
6
–
Description
Timer 2 overflow Flag
Must be cleared by software.
Set by hardware on Timer 2 overflow, if RCLK = 0 and TCLK = 0.
Timer 2 External Flag
Set when a capture or a reload is caused by a negative transition on T2EX pin if
EXEN2 = 1.
When set, causes the CPU to vector to Timer 2 interrupt routine when Timer 2
interrupt is enabled.
Must be cleared by software. EXF2 doesn’t cause an interrupt in Up/down
counter mode (DCEN = 1)
Receive Clock bit for UART
Cleared to use Timer 1 overflow as receive clock for serial port in mode 1 or 3.
Set to use Timer 2 overflow as receive clock for serial port in mode 1 or 3.
Transmit Clock bit for UART
Cleared to use Timer 1 overflow as transmit clock for serial port in mode 1 or 3.
Set to use Timer 2 overflow as transmit clock for serial port in mode 1 or 3.
Timer 2 External Enable bit
Cleared to ignore events on T2EX pin for Timer 2 operation.
Set to cause a capture or reload when a negative transition on T2EX pin is
detected, if Timer 2 is not used to clock the serial port.
Timer 2 Run control bit
Cleared to turn off Timer 2.
Set to turn on Timer 2.
Timer/Counter 2 select bit
Cleared for timer operation (input from internal clock system: F
Set for counter operation (input from T2 input pin, falling edge trigger). Must be 0
for clock out mode.
Timer 2 Capture/Reload bit
If RCLK = 1 or TCLK = 1, CP/RL2# is ignored and timer is forced to Auto-reload
on Timer 2 overflow.
Cleared to Auto-reload on Timer 2 overflows or negative transitions on T2EX pin
if EXEN2 = 1.
Set to capture on negative transitions on T2EX pin if EXEN2 = 1.
RCLK
5
5
–
TCLK
4
4
–
EXEN2
3
3
–
TR2
2
2
–
C/T2#
1
–
1
CLK PERIPH
CP/RL2#
).
0
–
0
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