TMPR4937 datasheet(540/552 Pages) TOSHIBA

540 / 552 page

Chapter 23 Notes on Use of TMPR4937

23-10

23.5 Notes on Serial I/O Port

•

Restrictions on use of the break function in SIO

[Restriction]

To transmit breaks to TX4937, synchronize breaks to the start bit. Set consecutively the transmit data

to Low immediately after the start bit.

[Violation]

When the transmitting end transmits breaks to TX4937 in the middle of a transmission, TX4937

detects the first flame error only, but not breaks.

When the break reception is synchronized to the start bit (the receive data is consecutively set to Low

immediately after the start bit), breaks can be detected correctly.

When breaks are transmitted to TX4937, it may not receive breaks.

This malfunction may occur when the transmitting end transmits breaks to TX4937 in the middle of a

transmission.

[Workarounds]

To transmit breaks to TX4937, synchronize breaks to the start bit (set the transmitting data

consecutively to Low immediately after the start bit).

(Malfunction)

Status

S 1 2 3 4 5 6 7 8 P S

SIN

* Since the start bit is not recognized after a flame error, the receiving status is stopped in idle state.

↑

Start

↑

Flame Error

(Correct operation)

Status

S 1 2 3 4 5 6 7 8 P S S 1 2 3 4 5 6 7 8 P S

SIN

* When the receiving data is consecutively set to Low immediately after the start bit is recognized,

breaks can be detected.

↑

Start

↑

1st Break

↑

2nd Break

TMPR4937 Datasheet(PDF) 540 Page - Toshiba Semiconductor