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Reception interrupt generation and flag set timing – FUJITSU F2MCTM-16LX User Manual

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CHAPTER 20 LIN-UART

20.5.1

Reception Interrupt Generation and Flag Set Timing

The following are the reception interrupt causes: completion of reception (SSR: RDRF)
and occurrence of a reception error (SSR: PE, ORE, or FRE).

Reception Interrupt Generation and Flag Set Timing

The received data is stored in the RDR register if the first stop bit is detected in mode 0, 1, 2 (if SSM = 1),

3, or the last data bit was read in mode 2 (if SSM = 0).

Each flag is set if the received data is completed (RDRF = 1) and the reception error (PE, ORE, FRE) of the

Serial Status Register (SSR) was set to "1". In this case, if the reception interrupt is enabled (SSR: RIE=1),

reception interrupt occurs.

Note:

If a reception error has occurred, the Reception Data Register (RDR) contains invalid data in each

mode.

Figure 20.5-1 shows the reception operation and flag set timing.

Figure 20.5-1 Reception Operation and Flag Set Timing

Note:

The example in Figure 20.5-1 does not show all possible reception options for mode 0. Here it is: "7p1"

and "8N1" (p = "E" [even] or "O" [odd]).

RDRF

PE

*1

, FRE

ORE

*2

(RDRF = "1")

ST

D0

D1

D2

D5

D6

D7/P

SP

ST

ST

D0

D1

D2

D6

D7

A/D

SP

ST

D0

D1

D2

D4

D5

D6

D7

D0

Receive data
(mode 0/3)

Receive data
(mode 1)

Receive data
(mode 2)

Reception interrupt occurs

*1: The PE flag will always remain "0" in mode 1 or 3.
*2: ORE only occurs, if next data is transferred before the reception data is read (RDRF=1).
ST: Start Bit SP: Stop Bit A/D: Mode 1 (multiprocessor) address/data selection bit

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