APPOTECH CW6632B - Page 95

10 SPI 89
CW6632B Bluetooth 3.0 Audio Player SOC Version 1.0.0
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Register 10–9 SPI1BUF – SPI1 Data Buffer
Position
7
6
5
4
3
2
1
0
Name
SPI1BUF
Default
X
x
x
x
x
x
x
X
Access
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Write this location to load the data to transmitter buffer and kick start the SPI transmission, read this location will
read the data from the receiver buffer.
Register 10–10 SPI1DMASPH– SPI1 DMA Pointer
Position
7
6
5
4
3
2
1
0
Name
-
-
SPI1DMASPH
Default
0
0
x
x
x
x
x
x
Access
-
-
WO
WO
WO
WO
WO
WO
SPI DMA start address pointer, point to the start address in IRAM that the data to be transmitted or data to be stored.
Register 10–11 SPI1DMASPL– SPI1 DMA Pointer
Position
7
6
5
4
3
2
1
0
Name
SPI1DMASPL
Default
x
x
x
x
x
x
x
x
Access
WO
WO
WO
WO
WO
WO
WO
WO
Register 10–12 SPI1DMACNTH – SPI1 DMA Counter High byte
Position
7
6
5
4
3
2
1
0
Name
SPI1DMACNTH
Default
X
X
x
X
x
x
x
x
Access
WO
WO
WO
WO
WO
WO
WO
WO
Register 10–13 SPI1DMACNTL – SPI1 DMA Counter Low Byte
Position
7
6
5
4
3
2
1
0
Name
SPI1DMACNTL
Default
X
x
x
x
x
x
x
x
Access
WO
WO
WO
WO
WO
WO
WO
WO
SPI DMA counter, decide the amount of units to be transmitted or received. There is 2 bytes in a unit. DMA counter
is range from 0 to 2047 words. And there is a formula as follow:
SPIDMACNT = {SPIDMACNTH, SPIDMACNTL}
Nunit = SPIDMACNT + 1
Nbyte = Nunit * 2 = (SPIDMACNT + 1) * 2
Write this location will enable DMA and kick start a DMA process .Caution: do not write 0 to this register.
Note: Must write SPIDMACNTH, then write SPIDMACNTL, this order can‟t change ! ! !
Register 10–14 SPI1BAUD – SPI1 BAUD RATE
Position
7
6
5
4
3
2
1
0