IV ANALOG BLOCK: A/D CONVERTER
Setting the sampling time
The A/D converter contains ST[1:0] (D[1:0]) / A/D sampling register (0x40245) that allows the
However, this register should be used as set by default (ST = "11"; x9 clock periods).
Control and Operation of A/D Conversion
Figure 2.2 shows the operation of the A/D converter.
ADE
Trigger
ADST
A/D operation
ADD
ADF
OWE
Interrupt request
ADE
Trigger
ADST
A/D operation
ADD
ADF
OWE
Interrupt request
(When AD0 to AD2 are converted)
| Sampling | Conversion | Sampling | Conversion | Sampling | Conversion | |||||
| AD0 | AD0 |
| AD1 | AD1 | AD2 | AD2 |
|
| ||
|
|
| |||||||||
|
|
| AD0 converted data | AD1 converted data AD2 converted data | |||||||
|
|
|
|
|
|
|
|
|
| ADD is overwritten | |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
(1) Normal mode
| (When only AD0 is converted) |
|
|
| Reset in software |
|
|
|
| ||
| Sampling Conversion Sampling Conversion | Sampling Conversion | |||
(2) Continuous mode
Figure 2.2 Operation of A/D Converter
Starting up the A/D converter circuit
After the settings specified in the preceding section have been made, write "1" to ADE (D2) / A/D enable register (0x40244) to enable the A/D converter. The A/D converter is thereby readied to accept a trigger to start A/D conversion. To set the A/D converter again, or if it is not be used, set ADE to "0".
Starting A/D conversion
When a trigger is input while ADE = "1", A/D conversion is started. If a software trigger has been selected, A/D conversion is started by writing "1" to ADST (D1) / A/D enable register (0x40244).
Only the trigger selected using TS[1:0] (D[4:3]) / A/D trigger register (0x40242) are valid; no other trigger is accepted.
A/D
S1C33L03 FUNCTION PART | EPSON |