Usart interrupts – FUJITSU MB91460 SERIES FR60 User Manual
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Chapter 32 USART (LIN / FIFO)
5.USART Interrupts
5. USART Interrupts
The USART uses both reception and transmission interrupts. An interrupt request can be generated for either
of the following causes:
• Receive data is set in the Reception Data Register (RDR04), or a reception error occurs.
• Transmission data is transferred from the Transmission Data Register (TDR04) to the transmission shift
register.
• A LIN break is detected
• No bus activity (neither reception nor transmission)
■
USART Interrupts
x
: Used
*
: Only available if ECCR04/SSM = 1
■
Reception Interrupt
If one of the following events occur in reception mode, the corresponding flag bit of the Serial Status Register
(SSR04) is set to "1":
• - Data reception is complete, i. e. the received data was transferred from the serial input shift register to the
Reception Data Register (RDR04) and data can be read: RDRF (if FIFO is enabled, trigger level is reached)
• - Overrun error, i. e. RDRF = 1 and RDR04 was not read by the CPU: ORE
Table 5-1 Interrupt control bits and interrupt causes of USART
Reception/
transmission/
ICU
Interrupt
request
flag bit
Flag
Register
Operation
mode
Interrupt
cause
Interrupt
cause
enable bit
How to clear
the Interrupt
Request
0
1
2
3
Reception
RDRF
SSR04
x
x
x
x
receive data is
written to RDR
(FIFO level reached)
SSR04 :
RIE
Receive data
is read
ORE
SSR04
x
x
x
x
Overrun error
"1" is written to
clear rec. error
bit (SCR04:
CRE)
FRE
SSR04
x
x
*
x
Framing error
PE
SSR04
x
*
Parity error
LBD
ESCR04
x
x
LIN synch break
detected
ESCR04 :
LBIE
"0" is written to
ESCR04 : LBD
TBI &
RBI
ESCR04
x
x
x
no bus activity
ECCR04 :
BIE
Receive data /
Send data
Transmission
TDRE
SSR04
x
x
x
x
Empty transmission
register
SSR04 :
TIE
Transfer data is
written
Input
Capture Unit
ICP4
IPCP4
x
x
1st falling edge of
LIN synch field
IPCP4 :
ICE4
disable ICE4
temporary
ICP4
IPCP4
x
x
5th falling edge of
LIN synch field
IPCP4 :
ICE4
disable ICE4