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2.14 CopyData Function
CopyData
Call peripheral-specific
GetWordData to read
Yes
No
Return
BlockHeader.BlockSize
BlockSize=
0x0000
?
Call GetLongData
to read
BlockHeader.DestAddr
Transfer
BlockHeader.BlockSize
words of data from
port to memory
starting at DestAddr
2.15 SCI_Boot Function
DSP
SCIRXDA
SCITXDA
Host
(Data and program
source)
CopyData Function
Each of the bootloaders uses the same function to copy data from the port to the DSP SARAM. This
function is the CopyData() function. This function uses a pointer to a GetWordData function that is
initialized by each of the loaders to properly read data from that port. For example, when the SPI loader is
evoked, the GetWordData function pointer is initialized to point to the SPI-specific SPI_GetWordData
function. Thus when the CopyData() function is called, the correct port is accessed. The flow of the
CopyData function is shown in
.
Figure 2-9. Overview of CopyData Function
The SCI boot mode asynchronously transfers code from SCI-A to internal memory. This boot mode only
supports an incoming 8-bit data stream and follows the same data flow as outlined in
Figure 2-10. Overview of SCI Bootloader Operation
The DSP communicates with the external host device by communication through the SCI-A Peripheral.
The autobaud feature of the SCI port is used to lock baud rates with the host. For this reason the SCI
loader is very flexible and you can use a number of different baud rates to communicate with the DSP.
After each data transfer, the DSP will echo back the 8-bit character received to the host. In this manner,
the host can perform checks that each character was received by the DSP.
SPRU722C – November 2004 – Revised October 2006
Bootloader Features
33