82C836 Datasheet, PDF (30/205 Pages) List of Unclassifed Manufacturers – Single-Chip 386sx AT

s Reset Strap Options
Functional Description
Table 3-1. Pins for Strap Options
Signal
-DACK0
-DACK1
-DACK2
-DACK3
-DACK5
-DACK6
-DACK7
↑ = Pull-up
Strap Function
SENSE0
SENSE1
VIDEO
NA/STCYC
-EXRTC
Reserved
-ROM16
↓ = Pull-down
Description
Determines ICR 45H bit 0
Determines ICR 45 bit 1
Video on SD ↑ or XD bus ↓; also determines ICR 45H bit 2
-NA↑ or -STCYC ↓ Function
Internal RTC ↑ or external ↓
(Should be pulled up)
8-bit ROM ↑ or 16-bit ROM ↓
Figure 3-1. Pull-Low Function----Alternate Implementation
+5V
-XRST
10K
7407
-DACKn
SENSE0 and SENSE1 are general purpose and can be used according to specific system
requirements. -DACK2 can also be used as a general purpose SENSE2 if ICR44H is
appropriately programmed to specify where the video controller resides.
If external Real Time Clock is used (-DACK5 pulled low), the -RTCCS pin (MFP5)
should be connected to PWRGOOD through a diode as shown in Figure 3-2. This
insures that the standby enable bit (ICR 60H) will always be cleared on power-up.
Otherwise, the 82C836 could power-up with standby mode enabled, which would
prevent -DACK5 from being sampled properly. See the ICR 60H description in
Section 4, Configuration Registers for further explanation of standby initialization.
3-2 Revision 3.0
PRELIMINARY
Chips and Technologies, Inc.