Intel 80C186XL, User Manual

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8-27
INTERRUPT CONTROL UNIT
Figure 8-17. Interrupt Vector Register (Slave Mode Only)
8.5.1.2 End-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.
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
Bit
Mnemonic
Bit Name
Reset
State
Function
T4:0 Interrupt
Vector Type
Field 00000 Specifies the five most-significant bits of the
interrupt vector types for the internal interrupt
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.
A1196-A0
15 0
T
0 T
2 T
1 T
3 T
4