Intel 80C188XL - Manual (Page 124)

3-43
BUS INTERFACE UNIT
Figure 3-36. Latching HLDA
The removal of HOLD must be detected for at least one clock cycle to allow the BIU to regain
the bus and execute a refresh bus cycle. Should HOLD go active before the refresh bus cycle is
complete, the BIU will release the bus and generate HLDA.
3.7.2 Exiting HOLD
Figure 3-37 shows the timing associated with exiting the bus hold state. Normally a bus operation
(e.g., an instruction prefetch) occurs just after HOLD is released. In a 16-bit bus system, the upper
half of the bus (D15:8) floats.
A1535-0A
D Q Latched HLDA
RESET
HOLD
CLR
HLDA
PRE
+5