Intel 80C188XL Intvec, Register Mnemonic, Interrupt Control Unit, 8.5.1.2End-Of-InterruptRegister

Models: 80C186XL 80C188XL

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INTVEC

INTERRUPT CONTROL UNIT

Register Name:Interrupt Vector Register (Slave Mode only)

Register Mnemonic:

INTVEC

Register Function:Specifies the five most-significant bit of the interrupt vector types for the internal interrupt sources

15

T 4

 

 

 

0

T

T

T

T

3

2

1

0

 

 

 

 

 

 

 

A1196-A0

 

 

 

 

 

Bit

Bit Name

Reset

Function

 

Mnemonic

State

 

 

 

 

 

 

 

 

 

T4:0

Interrupt

00000

Specifies the five most-significant bits of the

 

 

Vector Type

 

interrupt vector types for the internal interrupt

 

 

Field

 

sources. The three least-significant bits are

 

 

 

 

fixed (see Table 8-5).

 

 

 

 

 

 

NOTE: Reserved register bits are shown with gray shading. Reserved bits must be written to a logic zero to ensure compatibility with future Intel products.

Figure 8-17. Interrupt Vector Register (Slave Mode Only)

8.5.1.2End-Of-Interrupt Register

The End-of-Interrupt (EOI) register has the same function in Slave mode as in Master mode. However, non-specific EOI commands are not supported, so the NSPEC bit is omitted from the register. Only specific EOI commands can be issued. To clear an In-Service bit in Slave mode, write the three least-significant bits of the interrupt type (from Table 8-5) to the VT2:0 bits.

8-27

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Intel 80C188XL, 80C186XL user manual Intvec, Register Mnemonic, Interrupt Control Unit, 8.5.1.2End-Of-InterruptRegister