Public Version
McSPI Functional Description
www.ti.com
–
spim_clk phase, programmable with the PHA bit
The spim_clk frequency of a transfer is controlled by the external SPI master connected to the McSPI
slave device. The SPIm.
[5:2] CLKD field (with x=0) is not used in slave mode.
NOTE:
The configuration of the channel can be loaded in the SPIm.
register
(with x=0) only when the channel is disabled.
•
Two DMA request events, read and write, synchronize read/write accesses of the DMA controller with
the activity of McSPI. DMA requests are asserted using the SPIm.
[15] DMAR bit
(with x=0) for reading and the SPIm.
[14] DMAW bit (with x=0) for writing.
•
Four interrupt events (see
, Interrupt Events in Slave Mode)
20.5.3.2 Slave Transmit-and-Receive Mode
The slave receive mode is programmable (set the SPIm.
[13:12] TRM field (with x=0) to
0x0).
In slave transmit-and-receive mode, the
register must be loaded before McSPI is selected by
an external SPI master device.
After a channel is enabled, transmission and reception proceed with interrupt and DMA request events.
The
register content is always loaded in the shift register whether it is updated or not. The
event TXx_UNDERFLOW is activated accordingly and does not prevent transmission.
When an SPI word transfer completes (the SPIm.
0[2] EOT bit (with x=0) set to 1), the
received data is transferred to the channel receive register.
To use McSPI as a slave transmit-only device, the RXx_FULL and RX0_OVERFLOW interrupts and DMA
read requests must be disabled due to the
register state (see
, Interrupt
Events in Slave Mode).
20.5.3.3 Slave Transmit-Only Mode
The slave transmit-only mode is programmable (set the SPIm.
[13:12] TRM field (with
x=0) to 0x2) and avoids the requirement for the MPU to read the
register (minimizing data
movement) only when transmission is meaningful.
To use the McSPI as a slave transmit-only device, the RXx_FULL and RX0_OVERFLOW interrupts and
DMA read requests must be disabled because of the
register state.
When the SPI word transfer completes, the SPIm.
[2] EOT bit is set (with x=0).
shows a half-duplex system with a master device on the left and a transmit-only slave device
on the right. Each time a bit transfers out from the slave device, 1 bit transfers in the master. After eight
cycles of the serial clock spim_clk, WordB transfers from the slave to the master.
3000
Multichannel SPI
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 ...