MB90455 Series
46
10. 8/10-bit A/D Converter
The 8/10-bit A/D converter converts an analog input voltage into 8-bit or 10/bit digital value, using the RC-type
successive approximation conversion method.
Input signal is selected among 8 channels of analog input pins.
Activation trigger is selected among software trigger, internal timer output, and external trigger.
Functions of 8/10-bit A/D converter
The 8/10-bit A/D converter converts an analog voltage (input voltage) input to analog input pin into an 8-bit or
10-bit digital value (A/D conversion).
The 8/10-bit A/D converter has the following functions:
A/D conversion takes a minimum of 6.12
s*1 for one channel, including sampling time. (A/D conversion)
Sampling of one channel takes a minimum of 2.0
s*.
RC-type successive approximation conversion method, with sample & hold circuit is used for conversion.
Resolution of either 8 bits or 10 bits is specifiable.
A maximum of 8 channels of analog input pins are allowed for use.
Generation of interrupt request is allowed, by storing A/D conversion result in A/D data register.
Activation of EI2OS is allowed upon occurrence of an interrupt request. With use of EI2OS, data loss is avoided
even if A/D conversion is performed successively.
An activation trigger is selectable among software trigger, internal timer output, and external trigger (fall edge).
*: When operating with 16-MHz machine clock
8/10-bit A/D converter conversion mode
Conversion mode
Description
Singular conversion
mode
The A/D conversion is performed form a start channel to an end channel sequentially.
Upon completion of A/D conversion on an end channel, A/D conversion function stops.
Sequential conversion
mode
The A/D conversion is performed form a start channel to an end channel sequentially.
Upon completion of A/D conversion on an end channel, A/D conversion function
resumes from the start channel.
Pausing conversion
mode
The A/D conversion is performed by pausing at each channel. Upon completion of A/D
conversion on an end channel, A/D conversion and pause functions resume from the
start channel.