![NXP Semiconductors Kinetis KE1xZ256 Скачать руководство пользователя страница 1207](http://html1.mh-extra.com/html/nxp-semiconductors/kinetis-ke1xz256/kinetis-ke1xz256_reference-manual_17218131207.webp)
Writing 0 to CTRL[TE] does not immediately disable the transmitter. The current
transmit activity in progress must first be completed (that could include a data character,
idle character or break character), although the transmitter will not start transmitting
another character.
46.4.2.1 Send break and queued idle
The LPUART_CTRL[SBK] bit sends break characters originally used to gain the
attention of old teletype receivers. Break characters are a full character time of logic 0, 9-
bit to 12-bit times including the start and stop bits. A longer break of 13-bit times can be
enabled by setting LPUART_STAT[BRK13]. Normally, a program would wait for
LPUART_STAT[TDRE] to become set to indicate the last character of a message has
moved to the transmit shifter, write 1, and then write 0 to the LPUART_CTRL[SBK] bit.
This action queues a break character to be sent as soon as the shifter is available. If
LPUART_CTRL[SBK] remains 1 when the queued break moves into the shifter,
synchronized to the baud rate clock, an additional break character is queued. If the
receiving device is another Freescale Semiconductor LPUART, the break characters are
received as 0s in all data bits and a framing error (LPUART_STAT[FE] = 1) occurs.
A break character can also be transmitted by writing to the LPUART_DATA register
with bit 13 set and the data bits clear. This supports transmitting the break character as
part of the normal data stream and also allows the DMA to transmit a break character.
When idle-line wakeup is used, a full character time of idle (logic 1) is needed between
messages to wake up any sleeping receivers. Normally, a program would wait for
LPUART_STAT[TDRE] to become set to indicate the last character of a message has
moved to the transmit shifter, then write 0 and then write 1 to the LPUART_CTRL[TE]
bit. This action queues an idle character to be sent as soon as the shifter is available. As
long as the character in the shifter does not finish while LPUART_CTRL[TE] is cleared,
the LPUART transmitter never actually releases control of the TXD pin.
An idle character can also be transmitted by writing to the LPUART_DATA register with
bit 13 set and the data bits also set. This supports transmitting the idle character as part of
the normal data stream and also allows the DMA to transmit a break character.
The length of the break character is affected by the LPUART_STAT[BRK13],
LPUART_CTRL[M], LPUART_CTRL[M7], LPUART_BAUD[M10] and
LPUART_BAUD[SNBS] bits as shown below.
Chapter 46 Low Power Universal Asynchronous Receiver/Transmitter (LPUART)
Kinetis KE1xZ256 Sub-Family Reference Manual, Rev. 3, 07/2018
NXP Semiconductors
1207
Содержание Kinetis KE1xZ256
Страница 2: ...Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 2 NXP Semiconductors...
Страница 56: ...SysTick Clock Configuration Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 56 NXP Semiconductors...
Страница 62: ...Interrupt channel assignments Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 62 NXP Semiconductors...
Страница 124: ...Application information Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 124 NXP Semiconductors...
Страница 130: ...Initialization application information Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 130 NXP Semiconductors...
Страница 178: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 178 NXP Semiconductors...
Страница 356: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 356 NXP Semiconductors...
Страница 368: ...Module clocks Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 368 NXP Semiconductors...
Страница 410: ...Interrupts Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 410 NXP Semiconductors...
Страница 562: ...Power supply supervisor Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 562 NXP Semiconductors...
Страница 592: ...General security features Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 592 NXP Semiconductors...
Страница 604: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 604 NXP Semiconductors...
Страница 622: ...Application Information Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 622 NXP Semiconductors...
Страница 634: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 634 NXP Semiconductors...
Страница 674: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 674 NXP Semiconductors...
Страница 690: ...Module Signal Description Tables Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 690 NXP Semiconductors...
Страница 712: ...Functional description Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 712 NXP Semiconductors...
Страница 820: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 820 NXP Semiconductors...
Страница 1030: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1030 NXP Semiconductors...
Страница 1052: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1052 NXP Semiconductors...
Страница 1066: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1066 NXP Semiconductors...
Страница 1268: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1268 NXP Semiconductors...
Страница 1314: ...Usage Guide Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1314 NXP Semiconductors...
Страница 1316: ...Kinetis KE1xZ256 Sub Family Reference Manual Rev 3 07 2018 1316 NXP Semiconductors...