ADSP-BF535 Blackfin Processor Hardware Reference
10-19
SPI Compatible Port Controllers
an SPI transfer may be initiated (if
TIMOD = 00 in SPIx_CTL
). No such
hardware action occurs when the shadow register is read.
SPIx_SHADOW
is a
read-only register.
DMA Registers
The SPI DMA has two basic modes of operation—autobuffer and descrip-
tor. In autobuffer mode, all registers are read/write except the Current
Descriptor Pointer register, which is read-only. In this mode, the DMA
operates as a simple circular buffer. Autobuffer mode is enabled by writing
to bit 4 of the DMA configuration register. In descriptor mode, descriptor
work blocks are read from memory. In this mode, many registers and con-
figuration bits are no longer writable, since their values are loaded via
descriptors. These include the DMA Start Address and Count registers
and DMA Configuration register bits such as
TRAN
,
DATA SIZE BIT 0,
DATA SIZE BIT 1
, and
INTERRUPT ENABLE
. Descriptor mode is initiated by
writing to the Next Descriptor Pointer register, followed by a write to the
DMA Configuration register. For more information about DMA, see
“Direct Memory Access” on page 9-1
.
Figure 10-10. SPIx RDBR Shadow Register
Table 10-10. SPIx RDBR Shadow Register MMR Assignments
Register Name
Memory-Mapped Address
SPI0_SHADOW
0xFFC0 300C
SPI1_SHADOW
0xFFC0 340C
15 14
13 12 11 10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset = 0x0000
RDBR Shadow
SPIx RDBR Shadow Register (SPIx_SHADOW)
RO
For MMR
assignments, see
Table 10-10
.
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...