Interface Activation; Start Sequence - Texas Instruments OMAP5912 Reference Manual

Multichannel Serial Interfaces
Figure 44. Receive DMA Transfers
TI peripheral bus
dma add
Ad0 Ad1
dma data
Val0 dum
4.1.6

Interface Activation

Start Sequence

124 Serial Interfaces
ad
Adn
n-1
dum Valn
A multichannel application cannot use DMA for some channels and interrupt
servicing for others. RX/TX interrupts are not generated when DMA RX/TX
transfers are enabled.
A typical sequence to start the interface is:
1) MCSI configuration:
a) DSP_WRITE(0x0000)= CONTROL_REG in order to remove the write
protection on the control registers
b) DSP_WRITE(0x....)= MAIN_PARAMETERS_REG
c) DSP_WRITE(0x....)= INTERRUPTS_REG
d) DSP_WRITE(0x....)= CHANNEL_USED_REG
e) DSP_WRITE(0x....)= CLOCK_FREQUENCY_REG
f) DSP_WRITE(0x....)= OVER_CLOCK_REG
2) Transmit data loading for selected channels:
a) DSP_WRITE(0x....)= TX_REG[channel index]
3) Enable MCSI clock:
a) DSP_WRITE(0x0001)= CONTROL_REG
MCSI
MCSI Rx MCSI Rx
registers shift
registers
Value 0 Value 0
Dummy 1 Empty 1
Dummy n-1 Empty n-1
Value n Value n
Empty n+1 Empty n+1
Empty N Empty N
Serial input
Value 0 Value n
SPRU760B