R8C33A Datasheet, PDF (414/617 Pages) Renesas Technology Corp – MCU M16C FAMILY / R8C/Tiny SERIES

Under development ^{Preliminary specification}
Specifications in this manual are tentative and subject to change.
R8C/33A Group
24. Synchronous Serial Communication Unit (SSU)
24.5.1 Initialization in 4-Wire Bus Communication Mode
Figure 24.10 shows Initialization in 4-Wire Bus Communication Mode. Before the data transit/receive
operation, set the TE bit in the SSER register to 0 (transmit disabled), the RE bit in the SSER register to 0
(receive disabled), and initialize the synchronous serial communication unit.
To change the communication mode or format, set the TE bit to 0 and the RE bit to 0 before making the change.
Setting the RE bit to 0 does not change the settings of flags RDRF and ORER or the contents of the SSRDR
register.
Start
SSER register
RE bit ← 0
TE bit ← 0
SSMR2 register SSUMS bit ← 1
(1)
SSMR register Set bits CPHS and CPOS
(1) The MLS bit is set to 0 for MSB-first transfer.
MLS bits ← 0
The clock polarity and phase are set by bits
CPHS and CPOS.
SSCRH register
Set MSS bit
SSMR2 register SCKS bit ← 1
(2) Set the BIDE bit to 1 in bidirectional mode and
(2)
Set bits SOOS, CSS0 to
CSS1, and BIDE
set the I/O of the SCS pin by bits CSS0 and
CSS1.
SSCRH register Set bits CKS0 to CKS2
Set RSSTP bit
SSSR register
ORER bit ← 0 ⁽¹⁾
SSER register
RE bit ← 1 (receive)
TE bit ← 1 (transmit)
Set bits RIE, TEIE, and TIE
End
Note:
1. Write 0 after reading 1 to set the ORER bit to 0.
Figure 24.10 Initialization in 4-Wire Bus Communication Mode
REJ09B0455-0010 Rev.0.10 Feb 29, 2008
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