AT89C51ID2 Atmel Corporation, AT89C51ID2 Datasheet - Page 95

• Manufacturer Part Number: AT89C51ID2
• Manufacturer: Atmel Corporation

Specifications of AT89C51ID2

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 2
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

Registers
95
AT89C51ID2
Table 71. SSCON Register
SSCON - Synchronous Serial Control register (93h)
Table 72. SSDAT (095h) - Syncrhonous Serial Data register (read/write)
Number
Number
CR2
SD7
Bit
Bit
7
7
6
5
4
3
2
1
0
7
7
6
5
4
3
2
Mnemonic Description
Mnemonic Description
SSIE
SSIE
CR2
CR1
CR0
STA
ST0
SD6
SD7
SD6
SD5
SD4
SD3
SD2
Bit
Bit
AA
SI
6
6
Control Rate bit 2
See Table 65.
Synchronous Serial Interface Enable bit
Clear to disable the TWI module.
Set to enable the TWI module.
Start flag
Set to send a START condition on the bus.
Stop flag
Set to send a STOP condition on the bus.
Synchronous Serial Interrupt flag
Set by hardware when a serial interrupt is requested.
Must be cleared by software to acknowledge interrupt.
Assert Acknowledge flag
Clear in master and slave receiver modes, to force a not acknowledge (high level
on SDA).
Clear to disable SLA or GCA recognition.
Set to recognise SLA or GCA (if GC set) for entering slave receiver or transmitter
modes.
Set in master and slave receiver modes, to force an acknowledge (low level on
SDA).
This bit has no effect when in master transmitter mode.
Control Rate bit 1
See Table 65.
Control Rate bit 0
See Table 65.
Address bit 7 or Data bit 7.
Address bit 6 or Data bit 6.
Address bit 5 or Data bit 5.
Address bit 4 or Data bit 4.
Address bit 3 or Data bit 3.
Address bit 2 or Data bit 2.
STA
SD5
5
5
STO
SD4
4
4
SD3
SI
3
3
SD2
AA
2
2
CR1
SD1
1
1
4289C–8051–11/05
CR0
SD0
0
0