AT89LP214 Atmel Corporation, AT89LP214 Datasheet - Page 31

• Manufacturer Part Number: AT89LP214
• Manufacturer: Atmel Corporation

Specifications of AT89LP214

• Flash (kbytes): 2 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 12
• Spi: 1
• Uart: 1
• Sram (kbytes): 0.125
• Operating Voltage (vcc): 2.4 to 5.0
• Timers: 2
• Isp: SPI/OCD
• Watchdog: Yes

14.4
.
Table 14-1.
3538E–MICRO–11/10
Symbol
TF1
TR1
TF0
TR0
IE1
IT1
IE0
IT0
TCON = 88H
Bit Addressable
Bit
Mode 3 – 8-bit Split Timer
Function
Timer 1 overflow flag. Set by hardware on Timer/Counter overflow. Cleared by hardware when the processor vectors
to interrupt routine.
Timer 1 run control bit. Set/cleared by software to turn Timer/Counter on/off.
Timer 0 overflow flag. Set by hardware on Timer/Counter overflow. Cleared by hardware when the processor vectors
to interrupt routine.
Timer 0 run control bit. Set/cleared by software to turn Timer/Counter on/off.
Interrupt 1 edge flag. Set by hardware when external interrupt edge detected. Cleared when interrupt processed.
Interrupt 1 type control bit. Set/cleared by software to specify falling edge/low level triggered external interrupts.
Interrupt 0 edge flag. Set by hardware when external interrupt edge detected. Cleared when interrupt processed.
Interrupt 0 type control bit. Set/cleared by software to specify falling edge/low level triggered external interrupts.
TCON
TF1
7
– Timer/Counter Control Register
Timer 1 in Mode 3 simply holds its count. The effect is the same as setting TR1 = 0. Timer 0 in
Mode 3 establishes TL0 and TH0 as two separate counters. The logic for Mode 3 on Timer 0 is
shown in
locked into a timer function (counting machine cycles) and takes over the use of TR1 and TF1
from Timer 1. Thus, TH0 now controls the Timer 1 interrupt. While Timer 0 is in Mode 3, Timer 1
will still obey its settings in TMOD but cannot generate an interrupt.
Mode 3 is for applications requiring an extra 8-bit timer or counter. With Timer 0 in Mode 3, the
AT89LP213/214 can appear to have three Timer/Counters. When Timer 0 is in Mode 3, Timer 1
can be turned on and off by switching it out of and into its own Mode 3. In this case, Timer 1 can
still be used by the serial port as a baud rate generator or in any application not requiring an
interrupt.
Figure 14-4. Timer/Counter 0 Mode 3: Two 8-bit Counters
Note:
TR1
6
RH0/RL0 are not required by Timer 0 during Mode 3 and may be used as temporary storage
registers.
Figure
14-4. TL0 uses the Timer 0 control bits: C/T, GATE, TR0, INT0, and TF0. TH0 is
TF0
5
INT0 Pin
GATE
T0 Pin
÷TPS
÷TPS
TR0
4
C/T = 0
C/T =1
IE1
3
Control
Control
(8 Bits)
(8 Bits)
IT1
2
Reset Value = 0000 0000B
AT89LP213/214
IE0
1
Interrupt
Interrupt
IT0
0
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