AT89C51RE2 Atmel Corporation, AT89C51RE2 Datasheet - Page 116

• Manufacturer Part Number: AT89C51RE2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RE2

• Flash (kbytes): 128 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Spi: 1
• Uart: 2
• Sram (kbytes): 8.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART/OCD
• Watchdog: Yes

116
AT89C51RE2
Table 86. IPH1 Register
IPH1 - Interrupt Priority High Register (B3h)
Reset Value = XXXX 00X0b
Not bit addressable
Number
Bit
7
-
7
6
5
4
3
2
1
0
Mnemonic
PSH_1
KBDH
TWIH
SPIH
Bit
6
-
-
-
-
-
Description
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Serial port 1 Priority High bit
PSH_1 PSL_1 Priority Level
0
0
1
1
SPI interrupt Priority High bit
SPIH SPIL
0
0
1
1
TWI interrupt Priority High bit
TWIH TWIL
0
0
1
1
Keyboard interrupt Priority High bit
KB DH
0
0
1
1
5
-
1
0
1
0
1
0
1
0
1
0
0
1
KBDL Priority Level
0
1
0
1
Lowest
Highest
Priority Level
Lowest
Highest
Priority Level
Lowest
Highest
4
Highest
-
Lowest
PSH_1
3
SPIH
2
TWIH
1
7663E–8051–10/08
KBDH
0