Datasheet

573

• Bit 5—A/D Start (ADST): Selects start/end of A/D conversion. A1 is maintained during A/D

conversion start. It is also possible to set a 1 by the A/D conversion trigger input pin

(ADTRG).

Bit 5:

ADST Description

0 A/D conversion halted (Initial value)

1. Single mode: Starts A/D conversion. Automatically clears to 0 when conversion of

the designated channel is complete

2. Scan mode: Starts A/D conversion. Continuous conversion until cleared to 0 by the

software

• Bit 4—Scan Mode (SCAN): Selects the A/D conversion mode from single mode and scan

mode. For operations during single/scan mode, see section 16.4, Operation. When switching

modes, proceed while ADST=0.

Bit 4:

SCAN Description

0 Single mode (Initial value)

1 Scan mode

• Bit 3—Clock Select (CKS): Sets the A/D conversion time. Proceed conversion time switch

while adst=0. Always set CKS=0 when operating frequency exceeds 20MHz.

Bit 3:

CKS Description

0 Conversion time = 266 states (max) (Initial value)

1 Conversion time = 134 states (max)

• Bit 2—Reserved bit: Bit 2 always reads 0. Furthermore, always write 0.

• Bits 1, 0—Channel select 1, 0 (CH1, CH0): Selects the analog input channel along with the

SCAN bit. Switch channels while ADST=0.