SN8P26L38
8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 119
Version 1.5
11.5
SIOR REGISTER DESCRIPTION
SIOR initial value = 0000 0000
0B5H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
SIOR
SIOR7
SIOR6
SIOR5
SIOR4
SIOR3
SIOR2
SIOR1
SIOR0
Read/Write
W
W
W
W
W
W
W
W
After reset
0
0
0
0
0
0
0
0
The SIOR is designed for the SIO counter to reload the counted value when end of counting. It is like a post-scaler of
SIO clock source and let SIO has more flexible to setting SCK range. Users can set the SIOR value to setup SIO
transfer time. To setup SIOR value equation to desire transfer time is as following.
SCK frequency = (SIO rate / (256 - SIOR))/2
SIOR = 256 - ( 1 / ( 2*SCK frequency ) * SIO rate )
Example: Setup the SIO clock to be 5KHz. Fosc = 4MHz.
SIO’s rate = Fcpu = Fosc/4.
SIOR = 256
– (1/(2*5KHz) * 4MHz/4)
= 256
– (0.0001*1000000)
= 256
– 100
= 156