Intel 80C186XL, 80C188XL user manual 3.5.5Temporarily Exiting the HALT Bus State, Control

Models: 80C186XL 80C188XL

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3.5.5Temporarily Exiting the HALT Bus State

BUS INTERFACE UNIT

3.5.5Temporarily Exiting the HALT Bus State

A DMA request, refresh request or bus hold request causes the BIU to exit the HALT bus state temporarily. This can occur only when in the Active or Idle power management mode. The BIU returns to the HALT bus state after it completes the desired bus operation. However, the BIU does not execute another bus HALT cycle (i.e., ALE and bus cycle status are not regenerated). Figures 3-26, 3-27 and 3-28 illustrate how the BIU temporarily exits and then returns to the HALT bus state.

CLKOUT

HOLD

HLDA

AD15:0

AD7:0

A15:8

A19:16

CONTROL

A1516-0A

Figure 3-26. Returning to HALT After a HOLD/HLDA Bus Exchange

3-30

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Intel 80C186XL, 80C188XL 3.5.5Temporarily Exiting the HALT Bus State, CLKOUT HOLD HLDA AD15:0 AD7:0 A15:8 A19:16, Control