Microchip Technology DM183037 データシート
PIC18F97J94 FAMILY
DS30575A-page 478
2012 Microchip Technology Inc.
EXAMPLE 22-4:
CONVERTING A SINGLE CHANNEL 16 TIMES PER INTERRUPT
A/D Configuration:
• Select AN0 for S/H+ Input (CH0SA<4:0> = 00000)
• Select V
• Select AN0 for S/H+ Input (CH0SA<4:0> = 00000)
• Select V
R
- for S/H- Input (CH0NA<2:0> = 000)
• Configure for No Input Scan (CSCNA = 0)
• Use Only MUX A for Sampling (ALTS = 0)
• Set AD1IF on Every 16th Sample (SMPI<4:0> = 01111)
• Configure Buffers for Single, 16-Word Results (BUFM = 0)
• Use Only MUX A for Sampling (ALTS = 0)
• Set AD1IF on Every 16th Sample (SMPI<4:0> = 01111)
• Configure Buffers for Single, 16-Word Results (BUFM = 0)
Operational Sequence:
1.
1.
Sample MUX A Input AN0; Convert and Write to Buffer 0h.
2.
Sample MUX A Input AN0; Convert and Write to Buffer 1h.
3.
Sample MUX A Input AN0; Convert and Write to Buffer 2h.
4.
Sample MUX A Input AN0; Convert and Write to Buffer 3h.
5.
Sample MUX A Input AN0; Convert and Write to Buffer 4h.
6.
Sample MUX A Input AN0; Convert and Write to Buffer 5h.
7.
Sample MUX A Input AN0; Convert and Write to Buffer 6h.
8.
Sample MUX A Input AN0; Convert and Write to Buffer 7h.
9.
Sample MUX A Input AN0; Convert and Write to Buffer 8h.
10. Sample MUX A Input AN0; Convert and Write to Buffer 9h.
11. Sample MUX A Input AN0; Convert and Write to Buffer Ah.
12. Sample MUX A Input AN0; Convert and Write to Buffer Bh.
13. Sample MUX A Input AN0; Convert and Write to Buffer Ch.
14. Sample MUX A Input AN0; Convert and Write to Buffer Dh.
15. Sample MUX A Input AN0; Convert and Write to Buffer Eh.
16. Sample MUX A Input AN0; Convert and Write to Buffer Fh.
17. Set AD1IF Flag (and generate interrupt, if enabled).
18. Repeat (1-16) After Return from Interrupt.
11. Sample MUX A Input AN0; Convert and Write to Buffer Ah.
12. Sample MUX A Input AN0; Convert and Write to Buffer Bh.
13. Sample MUX A Input AN0; Convert and Write to Buffer Ch.
14. Sample MUX A Input AN0; Convert and Write to Buffer Dh.
15. Sample MUX A Input AN0; Convert and Write to Buffer Eh.
16. Sample MUX A Input AN0; Convert and Write to Buffer Fh.
17. Set AD1IF Flag (and generate interrupt, if enabled).
18. Repeat (1-16) After Return from Interrupt.
Results Stored in Buffer (after 2 cycles):
Buffer
Address
Buffer Contents
at 1st AD1IF Event
Buffer Contents
at 2nd AD1IF Event
ADC1BUF0
AN0, Sample 1
AN0, Sample 17
ADC1BUF1
AN0, Sample 2
AN0, Sample 18
ADC1BUF2
AN0, Sample 3
AN0, Sample 19
ADC1BUF3
AN0, Sample 4
AN0, Sample 20
ADC1BUF4
AN0, Sample 5
AN0, Sample 21
ADC1BUF5
AN0, Sample 6
AN0, Sample 22
ADC1BUF6
AN0, Sample 7
AN0, Sample 23
ADC1BUF7
AN0, Sample 8
AN0, Sample 24
ADC1BUF8
AN0, Sample 9
AN0, Sample 25
ADC1BUF9
AN0, Sample 10
AN0, Sample 26
ADC1BUFA
AN0, Sample 11
AN0, Sample 27
ADC1BUFB
AN0, Sample 12
AN0, Sample 28
ADC1BUFC
AN0, Sample 13
AN0, Sample 29
ADC1BUFD
AN0, Sample 14
AN0, Sample 30
ADC1BUFE
AN0, Sample 15
AN0, Sample 31
ADC1BUFF
AN0, Sample 16
AN0, Sample 32