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CHAPTER 17 UART
17.6.1
Baud Rates Determined Using the Dedicated Baud Rate
Generator
This section describes the baud rates that can be set when the clock from the dedicated
baud rate generator is selected as the UART transfer clock.
■
Baud Rates determined using the Dedicated Baud Rate Generator
When the transfer clock is generated using the dedicated baud rate generator, the machine clock is divided
with the machine clock prescaler. The divided machine clock is then divided by the transfer clock division
ratio selected with the clock selector again.The machine clock division ratios are common to the
asynchronous and synchronous baud rates, but different values set internally are selected as the transfer
clock division ratio for the asynchronous and synchronous baud rates.
The actual transfer rate can be calculated using the following formulas:
asynchronous baud rate =
φ
×
(prescaler division ratio)
×
(asynchronous transfer clock division ratio)
synchronous baud rate =
φ
×
(prescaler division ratio)
×
(synchronous transfer clock division ratio)
φ
: Machine clock frequency
●
Division ratios for the prescaler (common to asynchronous and synchronous baud rates)
Each machine clock division ratio is selected using the DIV2 to DIV0 bits of the CDCR register as listed in
Table 17.6-1 Selection of Each Division Ratio for the Machine Clock Prescaler
MD
DIV2
DIV1
DIV0
div
0
–
–
–
Setting not allowed
1
0
0
0
1
1
0
0
1
2
1
0
1
0
3
1
0
1
1
4
1
1
0
0
5
1
1
0
1
6
1
1
1
0
7
1
1
1
1
8
Summary of Contents for MB90460 Series
Page 1: ...The following document contains information on Cypress products ...
Page 3: ......
Page 5: ......
Page 9: ...iv ...
Page 41: ...22 CHAPTER 1 OVERVIEW ...
Page 45: ...26 CHAPTER 2 NOTES ON HANDLING DEVICES ...
Page 83: ...64 CHAPTER 3 CPU ...
Page 95: ...76 CHAPTER 4 RESET ...
Page 107: ...88 CHAPTER 5 CLOCK ...
Page 131: ...112 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Page 175: ...156 CHAPTER 7 INTERRUPT ...
Page 181: ...162 CHAPTER 8 MODE SETTING ...
Page 223: ...204 CHAPTER 9 I O PORT ...
Page 237: ...218 CHAPTER 10 TIME BASE TIMER ...
Page 247: ...228 CHAPTER 11 WATCHDOG TIMER ...
Page 275: ...256 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 373: ...354 CHAPTER 14 MULTI FUNCTIONAL TIMER ...
Page 485: ...466 CHAPTER 16 PWC Timer ...
Page 531: ...512 CHAPTER 17 UART ...
Page 559: ...540 CHAPTER 19 DELAYED INTERRUPT GENERATOR MODULE ...
Page 589: ...570 CHAPTER 20 8 10 BIT A D CONVERTER ...
Page 601: ...582 CHAPTER 21 ROM CORRECTION FUNCTION ...
Page 633: ...614 CHAPTER 23 512K 1024K BIT FLASH MEMORY ...
Page 645: ...626 CHAPTER 24 EXAMPLE OF F2 MC 16LX MB90F462 F462A F463A CONNECTION FOR SERIAL WRITING ...
Page 715: ...696 APPENDIX ...
Page 716: ...697 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 739: ......