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CHAPTER 15 UART
15.7 Send-Interrupt Generation and Flag Set Timing
A send interrupt is generated when the output-data register (SODR0-3) enables the
next unit of data to be written.
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Send-interrupt generation and flag set timing
When data from the output-data register (SODR0-3) is transferred to the send-shift register and
writing of the next unit of data is enabled, the send data empty flag bit (SSR0-3: TDRE) is set to
1. When the send data is written to the SODR0-3, the TDRE is cleared to 0. Figure 15.7-1
"Send operation and flag set timing" shows the send operation and flag set timing.
Figure 15.7-1 Send operation and flag set timing
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Timing of send-interrupt request generation
A send-interrupt request is issued immediately after the TDRE flag is set to 1 while send
interrupts are enabled (SSR0-3: TIE = 1).
Note:
A send completion interrupt is generated immediately when the send interrupt is enabled
(TIE = 1) because the initial status of the TDRE bit is 1. The TDRE bit is read-only and can
only be cleared when new data is written to the output-data register (SODR0-3). So, be
careful with the timing for enabling send interrupts.
D0
ST
SP
SP
A/D
D1
D2
D3
D4
D5
D6
D7
D0
ST
D1
D2
D3
D0
D1
D2
D3
D4
D5
D6
D7
D0
D1
D2
D3
D4
D5
D6
D7
ST: Start bit
D0-D7: Data bits
SP: Stop bit
A/D: Address/data selection bit
[Operation modes 0, 1]
[Operation mode 2]
Send-interrupt generation
Send-interrupt generation
Send-interrupt generation
Send-interrupt generation
SODR write
TDRE
SOUT output
SODR write
TDRE
SOUT output
Summary of Contents for MB91150 Series
Page 1: ......
Page 2: ......
Page 3: ...FUJITSU LIMITED FR30 32 BIT MICROCONTROLLER MB91150 Series HARDWARE MANUAL ...
Page 4: ......
Page 10: ...vi ...
Page 112: ...96 CHAPTER 3 MEMORY SPACE CPU AND CONTROL UNIT ...
Page 178: ...162 CHAPTER 5 I O PORTS ...
Page 214: ...198 CHAPTER 7 16 BIT RELOAD TIMER ...
Page 240: ...224 CHAPTER 8 PPG TIMER ...
Page 310: ...294 CHAPTER 13 8 10 BIT A D CONVERTER ...
Page 318: ...302 CHAPTER 14 8 BIT D A CONVERTER ...
Page 362: ...346 CHAPTER 15 UART ...
Page 420: ...404 CHAPTER 19 PERIPHERAL STOP CONTROL ...
Page 428: ...412 CHAPTER 20 CALENDAR MACROS ...
Page 503: ...487 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 510: ...494 INDEX ...
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