PIC12F629-I View Datasheet(PDF) - Microchip Technology
Part Name
Description
Manufacturer
PIC12F629-I Datasheet PDF : 132 Pages
| |||
PIC12F629/675
TABLE 7-1: TAD vs. DEVICE OPERATING FREQUENCIES
A/D Clock Source (TAD)
Device Frequency
Operation ADCS2:ADCS0
20 MHz
5 MHz
4 MHz
1.25 MHz
2 TOSC
000
4 TOSC
100
8 TOSC
001
16 TOSC
101
32 TOSC
010
64 TOSC
110
A/D RC
x11
100 ns(2)
200 ns(2)
400 ns(2)
800 ns(2)
1.6 µs
3.2 µs
2 - 6 µs(1,4)
400 ns(2)
800 ns(2)
1.6 µs
3.2 µs
6.4 µs
12.8 µs(3)
2 - 6 µs(1,4)
500 ns(2)
1.0 µs(2)
2.0 µs
4.0 µs
8.0 µs(3)
16.0 µs(3)
2 - 6 µs(1,4)
1.6 µs
3.2 µs
6.4 µs
12.8 µs(3)
25.6 µs(3)
51.2 µs(3)
2 - 6 µs(1,4)
Legend: Shaded cells are outside of recommended range.
Note 1: The A/D RC source has a typical TAD time of 4 µs for VDD > 3.0V.
2: These values violate the minimum required TAD time.
3: For faster conversion times, the selection of another clock source is recommended.
4: When the device frequency is greater than 1 MHz, the A/D RC clock source is only recommended if the
conversion will be performed during SLEEP.
7.1.5 STARTING A CONVERSION
The A/D conversion is initiated by setting the
GO/DONE bit (ADCON0<1>). When the conversion is
complete, the A/D module:
• Clears the GO/DONE bit
• Sets the ADIF flag (PIR1<6>)
• Generates an interrupt (if enabled).
If the conversion must be aborted, the GO/DONE bit
can be cleared in software. The ADRESH:ADRESL
registers will not be updated with the partially complete
A/D conversion sample. Instead, the
ADRESH:ADRESL registers will retain the value of the
previous conversion. After an aborted conversion, a
2 TAD delay is required before another acquisition can
be initiated. Following the delay, an input acquisition is
automatically started on the selected channel.
Note: The GO/DONE bit should not be set in the
same instruction that turns on the A/D.
7.1.6 CONVERSION OUTPUT
The A/D conversion can be supplied in two formats: left
or right shifted. The ADFM bit (ADCON0<7>) controls
the output format. Figure 7-2 shows the output formats.
FIGURE 7-2:
10-BIT A/D RESULT FORMAT
(ADFM = 0)
MSB
Bit 7
ADRESH
Bit 0
LSB
Bit 7
ADRESL
Bit 0
(ADFM = 1)
Bit 7
10-bit A/D Result
MSB
Bit 0
Bit 7
Unimplemented: Read as ‘0’
LSB
Bit 0
Unimplemented: Read as ‘0
10-bit A/D Result
DS41190C-page 42
2003 Microchip Technology Inc.
Share Link: 