SH7147 Datasheet, PDF (665/1108 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 15 A/D Converter (ADC)
Initial
Bit Bit Name Value
0 EXTRG 0
R/W Description
R/W Trigger Select
Selects the external trigger (ADTRG) or an A/D conversion
start trigger from the MTU2 or MTU2S as an A/D
conversion start trigger.
When the external trigger is selected (EXTRG = 1), upon
input of a low-level pulse to the ADTRG pin after the
TRGE bit is set to 1, the A/D converter detects the falling
edge of the pulse, and sets the ADST bit in ADCR to 1.
The operation which is performed when 1 is written to the
ADST bit by software is subsequently performed. A/D
conversion start by the external trigger input is enabled
only when the ADST bit is cleared to 0.
When the external trigger is used as an A/D conversion
start trigger, the low-level pulse input to the ADTRG pin
must be at least 1.5 Pφ clock cycles in width.
0: A/D converter is started by the A/D conversion start
trigger from the MTU2 or MTU2S
1: A/D converter is started by the external pin (ADTRG)
Rev. 3.00 Oct. 06, 2008 Page 641 of 1080
REJ09B0230-0300