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CHAPTER 15 UART
15.5 Interrupts
The UART has receive interrupts and send interrupts. Interrupt requests are generated
in the following cases:
• When receive data is set in the input-data register (SIDR0-3) or when a receive error
occurs
• When send data is transferred from the output-data register (SODR0-3) to the send-
shift register
■
UART interrupts
Table 15.5-1 "UART interrupt control bit and interrupt sources" shows the UART interrupt
control bit and interrupt sources.
❍
Receive interrupt
In receive mode, if data reception is completed (SSR0-3: RDRF), if an overrun error occurs
(SSR0-3: ORE), if a framing error occurs (SSR0-3: FRE), or if a parity error occurs (SSR0-3:
PE), the corresponding flag bit is set to 1. If the receive interrupt is enabled (SSR0-3: RIE = 1)
when any of these flag bits is 1, a receive-interrupt request is output to the interrupt controller.
The receive data full flag (SSR0-3: RDRF) is automatically cleared to 0 when the input-data
register (SIDR0-3) is read. When the REC bit of the control register (SCR0-3) is set to 0, the
receive-error flags (SSR0-3: PE, ORE, FRE) are cleared to 0.
❍
Send interrupt
When send data is transferred from the output-data register (SODR0-3) to the transfer shift
register, the TDRE bit of the status register (SSR0-3) is set to 1. If the send interrupt is enabled
(SSR0-3: TIE = 1), a send-interrupt request is output to the interrupt controller.
Table 15.5-1 UART interrupt control bit and interrupt sources
Send or
receive
Interrupt
request flag
bit
Operation mode
Interrupt source
Interrupt
source
enable bit
Interrupt
request flag
clear
0
1
2
Receive
RDRF
o
o
o
Receive data is
loaded into the buffer
(SIDR0-3)
SSR0-3:RIE
Receive data is
read
ORE
o
o
o
An overrun error
occurs
The receive-
error flag-clear
bit (SCR0-3:
REC) is set to 0
FRE
o
o
x
A framing error
occurs
PE
o
x
x
A parity error occurs
Send
TDRE
o
o
o
Send buffer
(SODR0-3) is empty
SSR0-3:TIE
Send data is
written
o: Used bit
x: Unused bit
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 ...
Page 512: ......