676
Chapter 16
Clocked Serial Interface B (CSIB)
User’s Manual U16580EE3V1UD00
16.7.3 Baud rate generation
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.
Remarks: 1.
f
BRGm
: BRGm count clock
2.
f
BGCSm
: Clock frequency selected by the BGCSm1, BGCSm0 bits of the PRSMm
register.
3.
f
XX
:
Main clock oscillation frequency
4.
k:
PRSMm register setting value (2
≤
k
≤
5)
5.
N:
PRSCMm register setting value (1 to 255), when PRSCMm = 01H to FFH,
or N = 256, when PRSCMm = 00H.
6.
m = 0, 1
16.8 Cautions
In communication modes where CBnCTL1.CBnDAP bit = 1, the CBnSTR.CBnTSF bit is cleared half a
SCKBn clock after occurrence of a reception completion interrupt (INTCBnR).
In the single transfer mode, writing the next transmit data is ignored during communication
(CBnTSF bit = 1), and the next transfer is not started. Also if reception-only communication
(CBnCTL0.CBnTXE bit = 0, CBnCTL0.CBnRXE bit = 1) is set, the next transfer is not started even if the
receive data is read during communication (CBnTSF bit = 1).
Therefore, when using the single transfer mode with communication modes where CBnCTL1.CBnDAP
bit = 1, pay particular attention to the following:
•
To start the next transmission, first confirm that CBnTSF bit = 0, and then write the transmit data to
the CBnTX register.
•
To perform the next reception continuously in reception-only mode (CBnTXE = 0, CBnRXE = 1),
confirm that CBnTSF bit = 0, and then read the CBnRX register.
If communication is supported by DMA transfer function, only communication modes with CBnDAP
bit = 0 should be used.
f
BRGm
f
BGCSm
N
2
×
--------------------
f
XX
2
k
N
2
×
×
--------------------------
=
=
Summary of Contents for MuPD70F3187
Page 6: ...6 Preface User s Manual U16580EE3V1UD00 ...
Page 16: ...16 User s Manual U16580EE3V1UD00 ...
Page 28: ...28 User s Manual U16580EE3V1UD00 ...
Page 32: ...32 User s Manual U16580EE3V1UD00 ...
Page 84: ...84 Chapter 2 Pin Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 144: ...144 Chapter 3 CPU Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 312: ...312 Chapter 9 16 Bit Timer Event Counter P User s Manual U16580EE3V1UD00 MEMO ...
Page 534: ...534 Chapter 11 16 bit Timer Event Counter T User s Manual U16580EE3V1UD00 ...
Page 969: ...969 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 970: ...970 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 ...
Page 976: ...976 Chapter 22 Internal RAM Parity Check Function User s Manual U16580EE3V1UD00 MEMO ...
Page 984: ...984 Chapter 23 On Chip Debug Function OCD User s Manual U16580EE3V1UD00 MEMO ...
Page 1006: ...1006 Chapter 24 Flash Memory User s Manual U16580EE3V1UD00 MEMO ...
Page 1036: ...1036 Chapter 27 Recommended Soldering Conditions User s Manual U16580EE3V1UD00 MEMO ...
Page 1046: ...1046 Appendix A Index User s Manual U16580EE3V1UD00 MEMO ...
Page 1052: ...1052 User s Manual U16580EE3V1UD00 ...
Page 1053: ......