AT89LP51ED2 Atmel Corporation, AT89LP51ED2 Datasheet - Page 164

• Manufacturer Part Number: AT89LP51ED2
• Manufacturer: Atmel Corporation

Specifications of AT89LP51ED2

• 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
• Eeprom (bytes): 4096
• Self Program Memory: API
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 4
• Isp: SPI/OCD/UART
• Watchdog: Yes

Table 20-2.
Notes:
164
Symbol
CSB
CONB
CFB
CENB
CMB
ACSRB = ABH
Not Bit Addressable
Bit
1-0
2-0
1. CONB must be cleared to 0 before changing CSB
2. Debouncing modes require the use of Timer 1 to generate the sampling delay.
AT89LP51RD2/ED2/ID2 Preliminary
Function
Comparator B Positive Input Channel Select
Comparator B Input Connect
When CONB = 1 the analog input pins are connected to the comparator. When CONB = 0 the analog input pins are
disconnected from the comparator. CONB must be cleared to 0 before changing CSB[1-0] or RFB[1-0].
Comparator B Interrupt Flag
Set when the comparator output meets the conditions specified by the CMB [2-0] bits and CENB is set. The flag must be
cleared by software. The interrupt may be enabled/disabled by setting/clearing bit 6 of IE.
Comparator B Enable
Set this bit to enable the comparator. Clearing this bit will force the comparator output low and prevent further events
from setting CFB. When CENB = 1 the analog input pins, P2.4—P2.7, have their digital inputs disabled if they are
configured in input-only mode.
Comparator B Interrupt Mode
CMB2
CSB1
ACSRB
CSB1
0
0
1
1
0
0
0
0
1
1
1
1
7
– Analog Comparator B Control & Status Register
CMB1
CSB0
0
1
0
1
0
0
1
1
0
0
1
1
CSB0
6
B+ Channel
AIN0 (P2.4)
AIN1 (P2.5)
AIN2 (P2.6)
AIN3 (P2.7)
CMB0
0
1
0
1
0
1
0
1
CONB
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
CFB
(1)
1-0
4
.
(2)
CENB
3
(2)
(2)
CMB2
2
Reset Value = 1100 0000B
CMB1
1
CMB0
3714A–MICRO–7/11
0