
SN8P1700
8-bit micro-controller build-in 12-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 146
Revision 1.93
Figure 9-2 shows a typical transfer between two microcontrollers. Process 1 sends SCK for initial the data transfer.
Both processors must work in the same clock edge direction, then both controllers would send and receive data at the
same time.
Figure 9-2. SIO Data Transfer Diagram
SIOM MODE REGISTER
SIOM initial value = 0000 x000
0B4H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
SIOM
SENB START
SRATE1
SRATE0 0 SCKMD
SEDGE
TXRX
R/W R/W R/W R/W - R/W R/W R/W
SENB: SIO function control bit. 0 = disable (P5.0~P5.2 is general purpose port), 1 = enable (P5.0~P5.2 is SIO
pins).
START: SIO progress control bit. 0 = End of transfer, 1 = progressing.
SRATE1, 0: SIO’s transfer rate select bit. 00 = fcpu, 01 = fcpu/32, 10 = fcpu/16, 11 = fcpu/8.
SCKMD: SIO’s clock mode select bit. 0 = internal, 1 = external mode.
SEDGE: SIO’s transfer clock edge select bit. 0 = falling edge, 1 = raising edge.
TXRX: SIO’s transfer direction select bit. 0 = receiver only , 1 = transmitter/receiver full duplex.
Note 1: If SCKMD=1 for external clock, the SIO is in SLAVE mode.
If SCKMD=0 for internal clock, the SIO is in MASTER mode.
Note 2: Don’t set SENB and START bits in the same time. That makes the SIO function error.
MSB
LSB
MSB
LSB
PROCESS 1
PROCESS 2
SCK
SCK
SIO Clock
SDO
SDO
SDI
SDI
SIOB 8 Bit Buffer
SIOB 8 Bit Buffer
SIOM Register
SIOM Register
MSB
LSB
MSB
LSB
PROCESS 1
PROCESS 2
SCK
SCK
SIO Clock
SDO
SDO
SDI
SDI
SIOB 8 Bit Buffer
SIOB 8 Bit Buffer
SIOM Register
SIOM Register