W79E825A Datasheet, PDF (44/127 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E825A/824A/823B/822B Data Sheet
BIT NAME
FUNCTION
7-0 ACC.[7:0] The A or ACC register is the standard 8052 accumulator
ADC CONTROL REGISTER
Bit: 7
6
5
4
3
2
1
0
ADC.1
ADC.0
ADCEX ADCI
ADCS
RCCLK AADR1 AADR0
Mnemonic: ADCCON
Address: E1h
BIT NAME
FUNCTION
7 ADC.1
The ADC conversion result.
6 ADC.0
The ADC conversion result.
5 ADCEX
Enable STADC-triggered conversion
0: Conversion can only be started by software (i.e., by setting ADCS).
1: Conversion can be started by software or by a rising edge on STADC (pin
P1.4).
4 ADCI
ADC Interrupt flag:
This flag is set when the result of an A/D conversion is ready. This generates an
ADC interrupt, if it is enabled. The flag may be cleared by the ISR. While this flag
is 1, the ADC cannot start a new conversion. ADCI can not be set by software.
3 ADCS
ADC Start and Status: Set this bit to start an A/D conversion. It may also be set
by STADC if ADCEX is 1. This signal remains high while the ADC is busy and is
reset right after ADCI is set.
Notes:
1. It is recommended to clear ADCI before ADCS is set. However, if ADCI is
cleared and ADCS is set at the same time, a new A/D conversion may start
on the same channel.
2. Software clearing of ADCS will abort conversion in progress.
3. ADC cannot start a new conversion while ADCS or ADCI is high.
2 RCCLK
0: The CPU clock is used as ADC clock.
1: The internal RC clock is used as ADC clock.
1 AADR1 The ADC input select. See table below.
0 AADR0 The ADC input select. See table below.
ADCI
0
0
1
1
The ADCI and ADCS control the ADC conversion as below:
ADCS
ADC STATUS
0
ADC not busy; A conversion can be started.
1
ADC busy; Start of a new conversion is blocked.
0
Conversion completed; Start of a new conversion requires ADCI = 0.
1
This is an internal temporary state that user can ignore it.
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