Interrupts - Fujitsu 8FX Hardware Manual

CHAPTER 14 LIN-UART

14.4 Interrupts

14.4 Interrupts
The LIN-UART has receive interrupts and transmit interrupts, which are
generated by the following sources. An interrupt number and an interrupt
vector are assigned to each interrupt. In addition, it has a LIN synch field edge
detection interrupt function using the 8/16-bit composite timer interrupt.
• Receive interrupt
A receive interrupt occurs when received data is set in the LIN-UART receive
data register (RDR), or when a receive error occurs, or when a LIN synch
break is detected.
• Transmit interrupt
A transmit interrupt occurs when transmit data is transferred from the LIN-
UART transmit data register (TDR) to the transmit shift register, and data
transmission starts.
■ Receive Interrupt
Table 14.4-1 shows the control bits and interrupt sources of receive interrupts.
Table 14.4-1 Interrupt Control Bits and Interrupt Sources of Receive Interrupts
Interrupt Operating mode
Flag
request flag
register
bit
❍
RDRF SSR
❍
ORE SSR
❍
FRE SSR
❍
PE SSR
LBD ESCR
❍ : Bit to be used
× : Unused bit
: Usable only when ECCR:SSM = 1
● Receive interrupts
If one of the following operations occurs in reception mode, the bit in the LIN-UART serial
status register (SSR) corresponding to that operation is set to "1".
Data reception completed
Received data is transferred from the LIN-UART serial input shift register to the LIN-UART
receive data register (RDR) (RDRF = 1).
Overrun error
With RDRF = 1, the next serial data is received while the CPU has not read the RDR
register. (ORE = 1).
Framing error
A stop bit reception error occurs (FRE = 1).
Parity error
A parity detection error occurs (PE = 1).
206
Interrupt source
0 1 2 3
❍ ❍ ❍ Writing received data to RDR
❍ ❍ ❍ Overrun error
❍ ❍ Framing error
× ×
Parity error
❍ LIN synch break detection
× × ×
FUJITSU SEMICONDUCTOR LIMITED
MB95630H Series
Interrupt source Interrupt request flag
enable bit
Read received data
SSR:RIE
Write "1" to receive error
flag clear bit (SCR:CRE)
ESCR:LBIE Write "0" to ESCR:LBD
MN702-00009-2v0-E
clear