
500
CHAPTER 17 UART
17.7.1
Operation in Asynchronous Mode (Operation Modes 0
and 1)
When UART is used in operation mode 0 (normal mode) or operation mode 1
(multiprocessor mode), the asynchronous transfer mode is selected.
■
Operation in Asynchronous Mode
●
Transfer data format
Transfer data begins with the start bit (L level) and ends with the stop bit (H level). The data of the
specified data bit length is transferred in LSB first mode.
•
In operation mode 0, the length of data with no parity is fixed to 7 bits, and that of data with parity is
fixed to 8 bits.
•
In operation mode 1, the length of data is fixed to 8 bits with an address/data (A/D) selection bit added
instead of parity.
Figure 17.7-1 shows the data format in asynchronous mode.
Figure 17.7-1 Transfer Data Format (Operation Modes 0 and 1)
●
Transmission operation
Transmission data is written to the output data register (SODR0/SODR1) when the transmission data empty
flag bit (SSR0/SSR1: TDRE) is "1". This data is transmitted if the transmission operation is enabled
(SCR0/SCR1: TXE = 1).
The TDRE flag is again set to "1" when the transmission data is transferred to the transmission shift register
and its transmission starts. Then, the next piece of transmission data gets ready to be set. At this point, a
transmission interrupt request is output requesting that the next piece of transmission data be set in the
SODR0/SODR1 register if that request is enabled (SSR0/SSR1: TIE = 1). The TDRE flag is cleared to "0"
when the transmission data is written to SODR0/SODR1.
D7/P
S
P
S
T D0 D1 D2 D
3
D5
D4 D6
D7 A/D
S
P
S
T D0 D1 D2 D
3
D5
D4 D6
[Oper
a
tion mode 0]
[Oper
a
tion mode 1]
* : D7 (
b
it 7) when p
a
rity i
s
not provided
P (p
a
rity) when p
a
rity i
s
provided
S
T :
S
t
a
rt
b
it
S
P :
S
top
b
it
A/D : Addre
ss
/d
a
t
a
s
election
b
it in oper
a
tion mode 1 (m
u
ltiproce
ss
or mode)
*
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: ......