SN8F2280 Series
USB 2.0 Full-Speed 8-Bit Micro-Controller
11.2 SIOM MODE REGISTER
0B0H
Bit 7
SENB
R/W
0
Bit 6
START
R/W
0
Bit 5
SRATE1
R/W
Bit 4
SRATE0
R/W
Bit 3
MLSB
R/W
0
Bit 2
SCKMD
R/W
Bit 1
CPOL
R/W
0
Bit 0
CPHA
R/W
0
SIOM
Read/Write
After reset
0
0
0
Bit 7
SENB: SIO function control bit.
0 = Disable (P2.0~P2.2 is general purpose I/O port).
1 = Enable (P2.0~P2.2 is SIO pins).
Bit 6
START: SIO progress control bit.
0 = End of transfer.
1 = Progressing.
Bit [5:4] SRATE1:0: SIO’s transfer rate select bit. These 2-bits are workless when SCKMD=1.
00 = Fcpu/2.
01 = Fcpu/64
10 = Fcpu/32
11 = Fcpu/16.
Bit 3
Bit 2
Bit 1
Bit 0
MLSB: MSB/LSB transfer first.
0 = MSB transmit first.
1 = LSB transmit first.
SCKMD: SIO’s clock mode select bit.
0 = Internal. (Master mode)
1 = External. (Slave mode)
CPOL: SIO’s transfer clock edge select bit.
0 = SCK idle status is low status
1 = SCK idle status is high status
CPHA: The Clock Phase bit controls the phase of the clock on which data is sampled.
0 = Data receive at the fisrt clock phase.
1 = Data receive at the second clock phase.
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.
2. Don’t set SENB and START bits in the same time. That makes the SIO function error.
Because SIO function is shared with Port2 for P2.0 as SCK, P2.1 as SDO and P2.2 as SDI.
The following table shown the Port2[2:0] I/O mode behavior and setting when SIO function enable and disable.
SENB=1 (SIO Function Enable)
(SCKMD=1)
P2.0 will change to Input mode automatically, no matter what P2M
SIO source = External clock
(SCKMD=0)
setting
P2.0/SCK
P2.0 will change to Output mode automatically, no matter what
SIO source = Internal clock
SIO = Transmitter/Receiver
P2M setting
P2.1/SDO
P2.2/SDI
P2.1 will change to Output mode automatically, no matter what
P2M setting
P2.2 must be set as Input mode in P2M ,or the SIO function will be abnormal
SENB=0 (SIO Function Disable)
P2.0/P2.1/P2.2 Port2[2:0] I/O mode are fully controlled by P2M when SIO function is disable
SONiX TECHNOLOGY CO., LTD
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Version 1.1
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