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Chapter 17
Clocked Serial Interface (CSIB)
Preliminary User’s Manual U17566EE1V2UM00
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PRSCMn - Prescaler compare registers
The PRSCMn registers are 8-bit compare registers.
Access
This register can be read/written in 8-bit units.
Address
<BRG_base> + 1
H
Initial Value
00
H
. This register is cleared by any reset.
Caution
1.
Do not rewrite the PRSCMn register during operation.
2.
Set the PRSCMn register before setting the PRSMn.BGCEn bit to 1.
17.7.3
Baud rate calculation
The transmission/reception clock is generated by dividing the main clock. The
baud rate generated from the main clock is obtained by the following equation.
Note
f
BRGn
:
BRGn count clock
f
SPCLK1
:
Main clock oscillation frequency
k:
PRSMn.BGCSn[1:0] register setting value (0
≤
k
≤
3)
N:
PRSCMn.PRSCMn[7:0] register value
if PRSCMn = 00H: N = 256.
7
6
5
4
3
2
1
0
PRSCMn7
PRSCMn6
PRSCMn5
PRSCMn4
PRSCMn3
PRSCMn2
PRSCMn1
PRSCMn0
R/W
f
BRGn
f
SPCLK1
2
k
N
×
2
×
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