Overview Of The A/D Converter - Fujitsu FR60 Hardware Manual

CHAPTER 12 A/D CONVERTER
12.1

Overview of the A/D Converter

The A/D converter converts an analog input voltage into digital value.
This section describes the A/D converter.
■ Features of the A/D Converter
The A/D converter has the following features:
Conversion time: Minimum of 1.48 µs per channel
•
• Serial/parallel conversion system with a sample & hold circuit
• Resolution of 10 bits (switchable between 8 bits and 10 bits)
• Selection of analog input from 12 channels by a program
Note: The MB91F353A/351A/352A/353A have only eight input channels.
• Conversion modes
Single conversion mode: Converts the input on a selected channel.
Scan conversion mode: Scan the input on up to 4 channels, and converts the input.
• Storage of converted data in a data buffer (A total of four data buffers are provided.)
• Possible generation of an interrupt request to the CPU to indicate the end of A/D conversion (DMA
transfer can be started by this interrupt request.)
• Selection of the conversion activation source from a program, external trigger (falling edge), and reload
timer channel 2 (rising edge)
■ Overview of the A/D Converter Registers
The A/D converter registers are shown below.
Address: 000078
Address: 00007A
Address: 00007C
Address: 00007E
Address: 000080
Address: 000082
364
Bit
15 8 7
ADCS2
H
ADCT
H
ADTH0
H
ADTH1
H
ADTH2
H
ADTH3
H
0
Control status register
ADCS1
Conversion time setting register
ADTL0 Converted-data register 0
ADTL1
Converted-data register 1
ADTL2
Converted-data register 2
ADTL3 Converted-data register 3