User manual

PICkit™ Serial Analyzer Firmware
© 2007 Microchip Technology Inc. DS51647A-page 87
9.7 SPI COMMUNICATIONS
SPI is a 4-wire serial protocol that uses data in, data out, clock and Chip Select pins. It
is a very basic protocol using a clock edge to capture data. The CONTROL_BLOCK is
used to enable SPI event markers, set the bit rate and configure transaction/protocol
options.
TABLE 9-20: CONNECTOR PINOUT IN SPI MODE
TABLE 9-21: SPI CONTROL BLOCK
Pin Description
1CS
2+V
3G
ND
4SDI
5SCK
6SDO
Byte Bit Description
COMM: SPI
16 7:0 Bit flags
0 1 = Event marker enable: read byte
1 1 = Event marker enable: write byte
2 1 = Event marker enable: status error
3 1 =
4 1 =
5 1 =
6 1 =
7 1 =
17 7:0 SPI Configuration bits
0 1 = SMP (sample phase)
1 1 = CKE (clock edge select)
2 1 = CKP (clock polarity)
3 1 = DAOD (disable auto output disable on data input)
4 1 = SS
5 1 =
6 1 = SLAVE
7 1 = MASTER
18 7:0
19 7:0
20 7:0
21 7:0
22 7:0 BIT RATE: Pre-scale code
23 7:0 BIT RATE: Scale code