Hardware manual

Rev. 3.0, 09/98, page 229 of 361
11.1.3 Input Pins
Table 11.1 lists the input pins used by the A/D converter module.
The eight analog input pins are divided into two groups, consisting of analog inputs 0 to 3 (AN
0
to
AN
3
) and analog inputs 4 to 7 (AN
4
to AN
7
), respectively.
Table 11.1 A/D Input Pins
Name Abbreviation I/O Function
Analog supply voltage AV
CC
Input Power supply and reference voltage for the
analog circuits.
Analog ground AV
SS
Input Ground and reference voltage for the analog
circuits.
Analog input 0 AN
0
Input Analog input pins, group 0
Analog input 1 AN
1
Input
Analog input 2 AN
2
Input
Analog input 3 AN
3
Input
Analog input 4 AN
4
Input
Analog input 5 AN
5
Input Analog input pins, group 1
Analog input 6 AN
6
Input
Analog input 7 AN
7
Input
A/D external trigger ADTRG Input External trigger for starting A/D conversion
11.1.4 Register Configuration
Table 11.2 lists the registers of the A/D converter module.
Table 11.2 A/D Registers
Name Abbreviation R/W Initial Value Address
A/D data register A ADDRA R H'00 H'FFE0
A/D data register B ADDRB R H'00 H'FFE2
A/D data register C ADDRC R H'00 H'FFE4
A/D data register D ADDRD R H'00 H'FFE6
A/D control/status register ADCSR R/(W)
*
H'00 H'FFE8
A/D control register ADCR R/W H'7E H'FFEA
Note: Software can write a “0” to clear bit 7, but cannot write a “1” in this bit.