AT89LP428 Atmel Corporation, AT89LP428 Datasheet - Page 43

• Manufacturer Part Number: AT89LP428
• Manufacturer: Atmel Corporation

Specifications of AT89LP428

• Flash (kbytes): 4 Kbytes
• Max. Operating Frequency: 25 MHz
• Cpu: 8051-1C
• Max I/o Pins: 30
• Spi: 1
• Uart: 1
• Sram (kbytes): 0.75
• Eeprom (bytes): 512
• Self Program Memory: IAP
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 3
• Isp: SPI/OCD
• Watchdog: Yes

11.3
3654A–MICRO–8/09
Mode 2 – 8-bit Auto-Reload Timer/Counter
Figure 11-2. Timer/Counter 1 Mode 1: 16-bit Auto-reload
Mode 2 configures the Timer register as an 8-bit Counter (TL1) with automatic reload, as shown
in
TH1, which is preset by software. The reload leaves TH1 unchanged. Mode 2 operation is the
same for Timer/Counter 0.
Figure 11-3. Timer/Counter 1 Mode 2: 8-bit Auto-reload
Note:
Figure
INT1 Pin
RH1/RL1 are not required by Timer 1 during Mode 2 and may be used as temporary storage
registers.
OSC
INT0 Pin
GATE
T1 Pin
11-3. Overflow from TL1 not only sets TF1, but also reloads TL1 with the contents of
OSC
T1 Pin
GATE
Mode 2:
TR1
÷TPS
÷TPS
TR1
Time-out Period
C/T = 0
C/T =1
C/T = 0
C/T = 1
Control
=
Control
------------------------------------------------------ -
Oscillator Frequency
(8 Bits)
(8 Bits)
(
256 TH0
RL1
TL1
(8 Bits)
(8 Bits)
TH1
TL1
–
(8 Bits)
(8 Bits)
RH1
TH1
)
AT89LP428/828
Reload
×
Reload
(
TPS
TF1
TF1
+
1
)
Interrupt
Interrupt
43