CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U14492EJ3V0UD
517
(2) Dedicated baud rate generator 3 (BRG3)
BRG3 is configured of an 8-bit timer counter that generates the baud rate signal, a prescaler mode register 3
(PRSM3) that controls baud rate signal generation, a prescaler compare register 3 (PRSCM3) that sets the
value of the 8-bit timer counter, and a prescaler.
(a) Input clock
The internal system clock (f
XX
) is input to BRG3.
(b) Prescaler mode register 3 (PRSM3)
The PRSM3 register controls generation of the CSI0 and CSI1 baud rate signals.
This register can be read/written in 8-bit or 1-bit units.
Cautions 1. Do not change the values of the BGCS1 and BGCS0 bits during transmission/
reception operation.
2. Set the PRSM3 register prior to setting the CSICAEn bit of the CSIMn register to 1
(n = 0, 1).
7
0
PRSM3
6
0
5
0
4
CE
3
0
2
0
1
BGCS1
0
BGCS0
Address
FFFFF920H
Initial value
00H
Bit Position
Bit Name
Function
4
CE
Enables baud rate counter operation.
0: Stop baud rate counter operation and fix baud rate output signal to 0.
1: Enable baud rate counter operation and start baud rate output operation.
Selects count clock for baud rate counter.
BGCS1
BGCS0
Count Clock Selection
0
0
f
XX
/4
0
1
f
XX
/8
1
0
f
XX
/16
1, 0
BGCS1,
BGCS0
1
1
f
XX
/32
Remark
f
XX
: Internal system clock
Содержание V850E/IA1 mPD703116
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