Motorola MVME172 manual SCC Interrupt Control Register

Models: MVME172

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Programming Model

SCC Interrupt Control Register

ADR/SIZ

 

 

 

$FFF4201C (8 bits)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BIT

23

22

21

 

20

19

 

18

17

16

 

 

 

 

 

 

 

 

 

 

 

NAME

 

 

INT

 

IEN

 

 

IL2

IL1

IL0

 

 

 

 

 

 

 

 

 

 

 

OPER

R

R

R

 

R/W

R

 

R/W

R/W

R/W

 

 

 

 

 

 

 

 

 

 

 

RESET

0

0

0 PL

 

0 PL

0

 

0 PL

0 PL

0 PL

 

 

 

 

 

 

 

 

 

 

 

IL2-IL0These three bits select the interrupt level for the SCC controller. Level 0 does not generate an interrupt.

IEN When this bit is set high, the interrupt is enabled. The interrupt is disabled when this bit is low.

INT This bit reflects the state of the INT pin from either Z85230 controller (qualified by the IEN bit). When this bit is high, an SCC controller interrupt is being generated at the level programmed in IL2-IL0. When the interrupt is cleared in the Z85230, INT returns to zero. During the interrupt acknowledge cycle, interrupts from the first Z85230 have priority over those from the second Z85230.

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Page 211
Image 211
Motorola MVME172 manual SCC Interrupt Control Register