Rainbow Electronics T89C5121 User Manual
Page 20

20
A/T8xC5121
4164G–SCR–07/06
Table 5. IE0 Register
IE0
Interrupt Enable Register (A8h)
Reset Value = 0XX0 0000b
7
6
5
4
3
2
1
0
EA
-
-
ES
ET1
EX1
ET0
EX0
Bit
Number
Bit
Mnemonic
Description
7
EA
Enable All interrupt bit
Clear to disable all interrupts.
Set to enable all interrupts.
If EA = 1, each interrupt source is individually enabled or disabled by setting or
clearing its interrupt enable bit.
6
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
5
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
4
ES
Serial port Enable bit
Clear to disable serial port interrupt.
Set to enable serial port interrupt.
3
ET1
Timer 1 overflow interrupt Enable bit
Clear to disable Timer 1 overflow interrupt.
Set to enable Timer 1 overflow interrupt.
2
EX1
External interrupt 1 Enable bit
Clear to disable external interrupt 1.
Set to enable external interrupt 1.
1
ET0
Timer 0 overflow interrupt Enable bit
Clear to disable Timer 0 overflow interrupt.
Set to enable Timer 0 overflow interrupt.
0
EX0
External interrupt 0 Enable bit
Clear to disable external interrupt 0.
Set to enable external interrupt 0.