Analog Devices SHARC ADSP-214 Series Hardware Reference Manual page 736

Programming Model
3. Send test data through the host device that can be used for calculat-
ing the baud rate of the incoming signal. A NULL character (0x00)
can be used for this purpose.
4. The baud rate can be derived from the width of timer as follows:
BAUDR = Width ÷ (8 × (number of zero data bits + 1)).
5. When using a NULL character, the number of zero data bits is 8.
Programs can also send some other pattern for this purpose. Once
the baud rate is calculated inside the timer ISR, the UART can be
programmed with the calculated baud rate.
Programming Model for DMA Transfers
The following is the general procedure for transferring data using DMA.
1. Clear the
2. Configure the UART DMA parameter registers (index, modify and
count).
3. Configure the
UARTMODE
4. Enable the DMA by setting the
/
TXCTL UARTRXCTL
Setting Up and Starting Chained DMA
To start a chain pointer DMA use the following steps.
1. Clear the chain pointer register
2. Initialize the chain pointer register with the address of the DMA
descriptor table. Set the
of each DMA block.
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/
UARTTXCTL UARTRXCTL
,
UARTLCR UARTDLL
registers.
registers.
bit if an interrupt is needed at the end
PCI
ADSP-214xx SHARC Processor Hardware Reference
register to zero.
, , ,
UARTDLH UARTIER
and bits in the
UARTEN DMAEN
and
UARTSCR
UART-