Programming Model

Programming the Programmable Clock

Programmable clock registers are defined in the following paragraphs.

The registers which control IP_c and IP_d are not used on the 200/300- Series MVME172.

programmable Clock Interrupt Control Register

ADR/SIZ

 

 

 

 

 

$FFFBC080 (8 bits)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BIT

7

6

 

5

 

 

4

 

3

 

2

 

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NAME

0

IRE

 

INT

 

IEN

 

ICLR

 

IL2

 

IL1

 

IL0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OPER

R

R/W

 

R

 

R/W

 

C

 

R/W

 

R/W

 

R/W

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESET

0 R

0 R

 

0 R

 

0 R

 

0 R

 

0 R

 

0 R

 

0 R

 

 

 

 

 

 

 

 

 

 

 

 

 

IL2-0

 

These three bits select the interrupt level for the

 

 

 

 

 

programmable clock interrupt. Level 0 does not generate

 

 

 

an interrupt.

 

 

 

 

 

 

 

 

ICLR

 

Writing a logic 1 to this bit clears the INT status bit. This

 

 

 

bit always reads as 0.

 

 

 

 

 

 

 

 

IEN

 

When IEN is set, the programmable clock interrupt is

 

 

 

enabled. When IEN is cleared, the interrupt is disabled.

 

INT

 

When this bit is high, an interrupt is being generated for

 

 

 

the programmable clock at the level programmed in IL2-

 

 

 

IL0.

 

 

 

 

 

 

 

 

 

 

 

IRE

 

This bit controls which action of the programmable clock

 

 

 

output causes interrupts.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Programmable Clock Action

 

 

 

 

 

 

IRE

 

 

That Causes Interrupts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

Rising Edge

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

Falling Edge

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

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Image 279
Motorola MVME172 manual Programming the Programmable Clock, Programmable Clock Interrupt Control Register, IL2-0, Ire