MB95630H Series
MN702-00009-1v0-E
FUJITSU SEMICONDUCTOR LIMITED
209
CHAPTER 14 LIN-UART
14.4 Interrupts
14.4.1
Timing of Receive Interrupt Generation and Flag
Set
A receive interrupt is generated when reception is completed (SSR:RDRF) or
when a reception error occurs (SSR:PE, ORE, FRE).
■
Timing of Receive Interrupt Generation and Flag Set
Received data is stored in the LIN-UART receive data register (RDR) when the first stop bit is
detected in operating mode 0/1/2(SSM = 1)/3, or when the last data bit is detected in operating
mode 2 (SSM = 0). When reception is completed (SSR:RDRF = 1), or when a reception error
occurs (SSR:PE, ORE, FRE = 1), an error flag corresponding to one of the events mentioned above
is set. If the receive interrupt has been enabled (SSR:RIE = 1) when an error flag is set, a receive
interrupt is generated.
Note:
In all operating modes, when a receive error occurs, data in the LIN-UART receive data
register (RDR) becomes invalid.
Figure 14.4-2 shows the timing of reception and flag set.
Figure 14.4-2 Timing of Reception and Flag Set
Note:
Figure 14.4-2 does not show all reception operations in mode 0. It only shows two
examples of reception operations using different communication formats. One reception
operation uses 7-bit data, a parity bit (parity bit = "even parity" or "odd parity") and one
stop bit. The other uses 8-bit data, no parity bit and one stop bit.
RDRF
PE
*1
, FRE
ORE
*2
(RDRF = 1)
S
T
D0
D1
D2
D5
D6
D7/P
S
P
S
T
S
T
D0
D1
D2
D6
D7
AD
S
P
S
T
D0
D1
D2
...
...
...
D4
D5
D6
D7
D0
Received data
(Operating mode 0/3)
Received data
(Operating mode 1)
Received data
(Operating mode 2)
Receive interrupts generated
*
1: The PE flag is always "0" in operating mode 1 and operating mode 3.
*
2: An overrun error occurs if the next data is transferred before received data is read (RDRF = 1).
ST: Start bit, SP: Stop bit, AD: Operating mode 1 (multiprocessor) address data select bit