Public Version
UART/IrDA/CIR Functional Description
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In transmit mode, an interrupt request is automatically asserted when the TX FIFO is empty. This request
is deasserted when the TX FIFO crosses the threshold level. The interrupt line is deasserted until a
sufficient number of elements is transmitted to go below the TX FIFO threshold.
19.4.2.3 FIFO Polled Mode Operation
In the FIFO polled mode (the UARTi.
[0] FIFO_EN bit is set to 0 and the relevant interrupts are
disabled by the UARTi.
register), the status of the receiver and transmitter can be checked by
polling the line status register (UARTi.
).
This mode is an alternative to the FIFO interrupt mode of operation in which the status of the receiver and
transmitter is automatically determined by sending interrupts to the MPU.
19.4.2.4 FIFO DMA Mode Operation
Although DMA operation includes four modes (DMA modes 0/1/2/3), the information in
assumes that mode 1 is used. (Mode 2 and mode 3 are legacy modes that use only one DMA request for
each module.)
In mode 2, the remaining DMA request is used for RX. In mode 3, the remaining DMA request is used for
TX.
The DMA requests in mode 2 and mode 3 use S_DMA_48, S_DMA_50, and S_DMA_52/D_DMA_10.
S_DMA_49, S_DMA_51, and S_DMA_53/D_DMA_11 are not used by the module in mode 2 and mode 3
and can be selected as follows:
•
When the UARTi.
[0] DMA_MODE_CTL bit is set to 0, setting the UARTi.
[3]
DMA_MODE bit to 0 enables DMA mode 0. Setting the DMA_MODE bit to 1 enables DMA mode 1.
•
When the DMA_MODE_CTL bit is set to 1, the UARTi.
[2:1] DMA_MODE_2 field determines
DMA mode 0 to 3 based on the supplementary control register (
) description.
For example:
•
If no DMA operation is desired, set the DMA_MODE_CTL bit to 1 and the DMA_MODE_2 field to 0x0.
(The DMA_MODE bit is discarded.)
•
If DMA mode 1 is desired, set either the DMA_MODE_CTL bit to 0 and the DMA_MODE bit to 1, or set
the DMA_MODE_CTL bit to 1 and the DMA_MODE_2 field to 01. (The DMA_MODE bit is discarded.)
If the FIFOs are disabled (the UARTi.
[0] FIFO_EN bit = 0), the DMA occurs in single-character
transfers.
When DMA mode 0 is programmed, the signals associated with DMA operation are not active.
19.4.2.4.1 DMA Transfers (DMA Mode 1, 2, or 3)
through
show the supported DMA operations.
2894
UART/IrDA/CIR
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated
Содержание OMAP36 Series
Страница 174: ...174 List of Tables SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 692: ...692 MPU Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1084: ...1084 IVA2 2 Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 1990: ...1990 2D 3D Graphics Accelerator SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2334: ...2334 Memory Subsystem SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2700: ...2700 Memory Management Units SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2868: ...2868 HDQ 1 Wire SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 2974: ...2974 UART IrDA CIR SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3054: ...3054 Multichannel SPI SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3462: ...3462 MMC SD SDIO Card Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3508: ...3508 General Purpose Interface SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3584: ...3584 Initialization SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...
Страница 3648: ...3648 Debug and Emulation SWPU177N December 2009 Revised November 2010 Copyright 2009 2010 Texas Instruments Incorporated ...