AT89LP213 Atmel Corporation, AT89LP213 Datasheet - Page 30

• Manufacturer Part Number: AT89LP213
• Manufacturer: Atmel Corporation

Specifications of AT89LP213

• Flash (kbytes): 2 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 14
• Spi: 1
• Sram (kbytes): 0.125
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 2
• Isp: SPI/OCD
• Watchdog: Yes

14.2
14.3
30
Mode 1 – 16-bit Auto-Reload Timer/Counter
Mode 2 – 8-bit Auto-reload Timer/Counter
AT89LP213/214
In Mode 1 the Timers are configured for 16-bit auto-reload. The Timer register is run with all
16 bits. The 16-bit reload value is stored in the high and low reload registers (RH1/RL1). The
clock is applied to the combined high and low timer registers (TH1/TL1). As clock pulses are
received, the timer counts up: 0000H, 0001H, 0002H, etc. An overflow occurs on the FFFFH-to-
0000H transition, upon which the timer register is reloaded with the value from RH1/RL1 and the
overflow flag bit in TCON is set. See
gives the full 16-bit timer period compatible with the standard 8051. Mode 1 operation is the
same for Timer/Counter 0.
Figure 14-2. 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 14-3. 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.
14-3. Overflow from TL1 not only sets TF1, but also reloads TL1 with the contents of
GATE
T1 Pin
OSC
Mode 1:
Mode 2:
OSC
TR1
INT0 Pin
÷TPS
T1 Pin
GATE
Time-out Period
Time-out Period
÷TPS
C/T = 0
C/T =1
TR1
Control
C/T = 0
C/T = 1
Figure
14-2. The reload registers default to 0000H, which
=
=
Control
(
---------------------------------------------------------
Oscillator Frequency
------------------------------------------------------ -
Oscillator Frequency
65536
(8 Bits)
(8 Bits)
(
RL1
TL1
256 TH0
(8 Bits)
(8 Bits)
TL1
TH1
–
{
–
RH0 RL0
(8 Bits)
(8 Bits)
RH1
TH1
,
Reload
)
}
TF1
)
×
×
Reload
(
(
TF1
TPS
Interrupt
TPS
+
+
1
1
3538E–MICRO–11/10
)
)
Interrupt