AT89LP51RD2 Atmel Corporation, AT89LP51RD2 Datasheet - Page 163

• Manufacturer Part Number: AT89LP51RD2
• Manufacturer: Atmel Corporation

Specifications of AT89LP51RD2

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 42
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Adc Channels: 7
• Adc Resolution (bits): 10
• Adc Speed (ksps): 153.8
• Sram (kbytes): 2.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 4
• Isp: SPI/OCD/UART
• Watchdog: Yes

Table 20-1.
Notes:
3714A–MICRO–7/11
Symbol
CSA
CONA
CFA
CENA
CMA
ACSRA = A3H
Not Bit Addressable
Bit
1-0
2-0
1. CONA must be cleared to 0 before changing CSA
2. Debouncing modes require the use of Timer 1 to generate the sampling delay.
Function
Comparator A Positive Input Channel Select
Comparator A Input Connect
When CONA = 1 the analog input pins are connected to the comparator. When CONA = 0 the analog input pins are
disconnected from the comparator. CONA must be cleared to 0 before changing CSA[1-0] or RFA[1-0].
Comparator A Interrupt Flag
Set when the comparator output meets the conditions specified by the CMA [2-0] bits and CENA is set. The flag must be
cleared by software. The interrupt may be enabled/disabled by setting/clearing bit 6 of IE.
Comparator A Enable
Set this bit to enable the comparator. Clearing this bit will force the comparator output low and prevent further events
from setting CFA. When CENA = 1 the analog input pins, P2.4—P2.7, have their digital inputs disabled if they are
configured in input-only mode.
Comparator A Interrupt Mode
CMA2
CSA1
ACSRA
CSA1
0
0
1
1
0
0
0
0
1
1
1
1
7
– Analog Comparator A Control & Status Register
CMA1
CSA0
0
1
0
1
0
0
1
1
0
0
1
1
CSA0
6
A+ Channel
AIN0 (P2.4)
AIN1 (P2.5)
AIN2 (P2.6)
AIN3 (P2.7)
CMA0
0
1
0
1
0
1
0
1
CONA
5
Interrupt Mode
Negative (Low) level
Positive edge
Toggle with debouncing
Positive edge with debouncing
Negative edge
Toggle
Negative edge with debouncing
Positive (High) level
AT89LP51RD2/ED2/ID2 Preliminary
CFA
(1)
1-0
4
.
(2)
CENA
3
(2)
(2)
CMA2
2
Reset Value = 0000 0000B
CMA1
1
CMA0
0
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