Intel 8XC251SA, User Manual

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8XC251SA, SB, SP, SQ USER’S MANUAL
C-16
IPL0
Address: S:B8H
Reset State: X000 0000B
Interrupt Priority Low Control Register 0. IPL0, together with IPH0, assigns each interrupt a priority
level from 0 (lowest) to 3 (highest):
IPH0. x IPL0. x Priority Level
0 0 0 (lowest priority)
0 1 1
1 0 2
1 1 3 (highest priority)
7 0
— IPL0.6 IPL0.5 IPL0.4 IPL0.3 IPL0.2 IPL0.1 IPL0.0
Bit
Number
Bit
Mnemonic
Function
7 — Reserved. The value read from this bit is indeterminate. Write a zero to
this bit.
6 IPL0.6 PCA Interrupt Priority Bit Low
5 IPL0.5 Timer 2 Overflow Interrupt Priority Bit Low
4 IPL0.4 Serial I/O Port Interrupt Priority Bit Low
3 IPL0.3 Timer 1 Overflow Interrupt Priority Bit Low
2 IPL0.2 External Interrupt 1 Priority Bit Low
1 IPL0.1 Timer 0 Overflow Interrupt Priority Bit Low
0 IPL0.0 External Interrupt 0 Priority Bit Low