A/D Converter Signals And Registers - Intel 8XC196K Series User Manual

8XC196K x , J x , CA USER'S MANUAL

11.2 A/D CONVERTER SIGNALS AND REGISTERS

Table 11-1 lists the A/D signals and Table 11-2 describes the control and status registers. Al-
though the analog inputs are multiplexed with I/O port pins, no configuration is necessary.
Port Pin A/D Signal
P0.7:0 ACH7:0 (K x )
P0.7:2 ACH7:2 (CA, J x )
— ANGND
— V
REF
Mnemonic Address
AD_COMMAND
AD_RESULT 1FAAH, 1FABH A/D Result
AD_TEST
AD_TIME
INT_MASK
INT_PEND
11-2
Table 11-1. A/D Converter Pins
A/D Signal
Type
I Analog Inputs
Input channels to the A/D converter. See the "Voltage on
Analog Input Pin" specification in the datasheet for
acceptable voltage ranges.
GND Reference Ground
Must be connected for A/D converter and port operation.
PWR Reference Voltage
Must be connected for A/D converter and port operation.
Table 11-2. A/D Control and Status Registers
1FACH A/D Command
This register selects the A/D channel, controls whether the A/D
conversion starts immediately or is triggered by the EPA, and
selects the operating mode.
For an A/D conversion, the high byte contains the eight MSBs from
the conversion, while the low byte contains the two LSBs from a 10-
bit conversion (undefined for an 8-bit conversion), indicates which
A/D channel was used, and indicates whether the channel is idle.
For a threshold-detection, calculate the value for the successive
approximation register and write that value to the high byte of
AD_RESULT. Clear the low byte or leave it in its default state.
1FAEH A/D Conversion Test
This register enables conversions on ANGND and V
specifies adjustments for zero-offset errors.
1FAFH A/D Conversion Time
This register defines the sample window time and the conversion
time for each bit.
0008H Interrupt Mask
The AD bit in this register enables or disables the A/D interrupt. Set
the AD bit to enable the interrupt request.
0009H Interrupt Pending
The AD bit in this register, when set, indicates that an A/D interrupt
request is pending.
Description
Description
REF
and