Datasheet

Section 20 A/D Converter
Rev. 4.00 Sep 27, 2006 page 617 of 1130
REJ09B0327-0400
The 10-bit data resulting from A/D conversion is transferred to the ADDR register for the selected
channel and stored there. The upper 8 bits of the converted data are transferred to the upper byte
(bits 15 to 8) of ADDR, and the lower 2 bits are transferred to the lower byte (bits 7 and 6) and
stored. Bits 5 to 0 are always read as 0.
The correspondence between the analog input channels and ADDR registers is shown in table
20.3.
The ADDR registers can always be read by the CPU. The upper byte can be read directly, but for
the lower byte, data transfer is performed via a temporary register (TEMP). For details, see section
20.3, Interface to Bus Master.
The ADDR registers are initialized to H'0000 by a reset, and in standby mode, watch mode,
subactive mode, subsleep mode, and module stop mode.
Table 20.3 Analog Input Channels and Corresponding ADDR Registers
Analog Input Channel
Group 0 Group 1 A/D Data Register
AN0 AN4 ADDRA
AN1 AN5 ADDRB
AN2 AN6 or CIN0 to CIN7 ADDRC
AN3 AN7 or CIN8 to CIN15 ADDRD
20.2.2 A/D Control/Status Register (ADCSR)
7
ADF
0
R/(W)
*
6
ADIE
0
R/W
5
ADST
0
R/W
4
SCAN
0
R/W
3
CKS
0
R/W
0
CH0
0
R/W
2
CH2
0
R/W
1
CH1
0
R/W
Bit
Initial value
Read/Write
Note: * Only 0 can be written in bit 7, to clear the flag.
ADCSR is an 8-bit readable/writable register that controls A/D conversion operations.
ADCSR is initialized to H'00 by a reset, and in standby mode, watch mode, subactive mode,
subsleep mode, and module stop mode.