Microchip Technology dsPIC30F - Page 418

dsPIC30F Family Reference Manual
DS70064C-page 17-42 © 2004 Microchip Technology Inc.
Table 17-7: Sampling Eight Inputs Using Simultaneous Sampling
CONTROL BITS OPERATION SEQUENCE
Sequence Select Sample MUX A Inputs:
SMPI<2:0> = 0011 (AN13-AN1) -> CH0, AN0 -> CH1, AN1 -> CH2, AN2 -> CH3
Interrupt on 4th sample Convert CH0, Write Buffer 0x0
CHPS<1:0> = 1x Convert CH1, Write Buffer 0x1
Sample Channels CH0, CH1, CH2, CH3 Convert CH2, Write Buffer 0x2
SIMSAM = 1 Convert CH3, Write Buffer 0x3
Sample all channels simultaneously Sample MUX B Inputs:
BUFM = 0 AN14 -> CH0,
Single 16-word result buffer (AN3-AN6) -> CH1, (AN4-AN7) -> CH2, (AN5-AN8) -> CH3
ALTS = 1 Convert CH0, Write Buffer 0x4
Alternate MUX A/MUX B input select Convert CH1, Write Buffer 0x5
MUX A Input Select Convert CH2, Write Buffer 0x6
CH0SA<3:0> = 1101 Convert CH3, Write Buffer 0x7
Select AN13 for CH0+ input Sample MUX A Inputs:
CH0NA = 1 (AN13-AN1) -> CH0, AN0 -> CH1, AN1 -> CH2, AN2 -> CH3
Select AN1 for CH0- input Convert CH0, Write Buffer 0x8
CSCNA = 0 Convert CH1, Write Buffer 0x9
No input scan Convert CH2, Write Buffer 0xA
CSSL<15:0> = n/a Convert CH3, Write Buffer 0xB
Scan input select unused Sample MUX B Inputs:
CH123SA = 0 AN14 -> CH0,
CH1+ = AN0, CH2+ = AN1, CH3+ = AN2 (AN3-AN6) -> CH1, (AN4-AN7) -> CH2, (AN5-AN8) -> CH3
CH123NA<1:0> = 0x Convert CH0, Write Buffer 0xC
CH1-, CH2-, CH3- = V
REF- Convert CH1, Write Buffer 0xD
MUX B Input Select Convert CH2, Write Buffer 0xE
CH0SB<3:0> = 1110 Convert CH3, Write Buffer 0xF
Select AN14 for CH0+ input Interrupt
CH0NB = 0 Repeat
Select V
REF- for CH0- input
CH123SB = 1
CH1+ = AN3, CH2+ = AN4, CH3+ = AN5
CH123NB<1:0> = 10
CH1- = AN6, CH2- = AN7, CH3- = AN8
Buffer
Address
Buffer @
1st Interrupt
Buffer @
2nd Interrupt
ADCBUF0 (AN13-AN1) sample 1 (AN13-AN1) sample 5
ADCBUF1 AN0 sample 1 AN0 sample 5
ADCBUF2 AN1 sample 1 AN1 sample 5
ADCBUF3 AN2 sample 1 AN2 sample 5
ADCBUF4 AN14 sample 2 AN14 sample 6
ADCBUF5 (AN3-AN6) sample 2 (AN3-AN6) sample 6
ADCBUF6 (AN4-AN7) sample 2 (AN4-AN7) sample 6
ADCBUF7 (AN5-AN8) sample 2 (AN5-AN8) sample 6 •••
ADCBUF8 (AN13-AN1) sample 3 (AN13-AN1) sample 7
ADCBUF9 AN0 sample 3 AN0 sample 7
ADCBUFA AN1 sample 3 AN1 sample 7
ADCBUFB AN2 sample 3 AN2 sample 7
ADCBUFC AN14 sample 4 AN14 sample 8
ADCBUFD (AN3-AN6) sample 4 (AN3-AN6) sample 8
ADCBUFE (AN4-AN7) sample 4 (AN4-AN7) sample 8
ADCBUFF (AN5-AN8) sample 4 (AN5-AN8) sample 8