AT89C51AC3 Atmel Corporation, AT89C51AC3 Datasheet - Page 92

• Manufacturer Part Number: AT89C51AC3
• Manufacturer: Atmel Corporation

Specifications of AT89C51AC3

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 62.5
• Sram (kbytes): 2.25
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

Serial Peripheral Status Register
and Control (SPSCR)
92
AT89C51AC3
Reset Value = 0001 0100b
Not bit addressable
The Serial Peripheral Status Register contains flags to signal the following conditions:
•
•
•
Table 49. SPSCR Register
SPSCR - Serial Peripheral Status and Control register (0D5H)
Bit Number
Number
SPIF
Data transfer complete
Write collision
Inconsistent logic level on SS pin (mode fault error)
Bit
7
7
6
5
3
2
1
0
Mnemonic Description
SPIF
OVR
Bit
Bit Mnemonic
6
-
-
CPOL
CPHA
SPR1
SPR0
Serial Peripheral Data Transfer Flag
Cleared by hardware to indicate data transfer is in progress or has been
approved by a clearing sequence.
Set by hardware to indicate that the data transfer has been completed.
This bit is cleared when reading or writing SPDATA after reading SPSCR.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Overrun Error Flag
- Set by hardware when a byte is received whereas SPIF is set (the previous
received data is not overwritten).
- Cleared by hardware when reading SPSCR
OVR
5
Description
Clock Polarity
Cleared to have the SCK set to ’0’ in idle state.
Set to have the SCK set to ’1’ in idle state.
Clock Phase
Cleared to have the data sampled when the SCK leaves the idle
state (see CPOL).
Set to have the data sampled when the SCK returns to idle state (see
CPOL).
SPR2
0
0
0
0
1
1
1
1
MODF
4
SPR1
0
0
1
1
0
0
1
1
SPR0 Serial Peripheral Rate
SPTE
0
1
0
1
0
1
0
1
3
Invalid
F
F
F
F
F
F
Invalid
CLK PERIPH
CLK PERIPH
CLK PERIPH
CLK PERIPH
CLK PERIPH
CLK PERIPH
UARTM
2
/4
/8
/16
/32
/64
/128
4383D–8051–02/08
SPTEIE
1
MODFIE
0