TMS320VC5421 Datasheet, PDF (30/88 Pages) Texas Instruments – DIGITAL SIGNAL PROCESSOR

TMS320VC5421
DIGITAL SIGNAL PROCESSOR
SPRS098 – DECEMBER 1999
multichannel buffered serial port (McBSP) (continued)
15
14
13
12
11
10
9
XCERyz15
XCERyz14
XCERyz13
XCERyz12
XCERyz11
XCERyz10
XCERyz9
RW,+0
RW,+0
RW,+0
RW,+0
RW,+0
RW,+0
RW,+0
7
6
5
4
3
2
1
XCERyz7
XCERyz6
XCERyz5
XCERy4
XCERyz3
XCERyz2
XCERyz1
RW,+0
RW,+0
RW,+0
RW,+0
RW,+0
RW,+0
RW,+0
Note: R = Read, W = Write, +0 = Value at reset; y = Partition A,B,C,D,E,F,G, or H; z = McBSP 0,1, or 2
8
XCERyz8
RW,+0
0
XCERyz0
RW,+0
Figure 12. Transmit Channel Enable Registers Bit Layout for Partitions A to H
Table 9. Transmit Channel Enable Registers for Partitions A to H
Bit
15–0
Name
XCERyz(15:0)
Function
Transmit Channel Enable Register
XCERyz n = 0 Disables transmit of nth channel in partition y.
XCERyz n = 1 Enables transmit of nth channel in partition y.
Note: y = Partition A,B,C,D,E,F,G, or H; z = McBSP 0,1, or 2; n = bit 15–0
The clock stop mode (CLKSTP) in the McBSP provides compatibility with the serial port interface (SPI) protocol.
Clock stop mode works with only single-phase frames and one word per frame. The word sizes supported by
the McBSP are programmable for 8-, 12-, 16-, 20-, 24-, or 32-bit operation. When the McBSP is configured to
operate in SPI mode, both the transmitter and the receiver operate together as a master or as a slave.
The McBSP is fully static and operates at arbitrarily low clock frequencies. The maximum McBSP multichannel
operating frequency on the ’5421 is 9 MBps. Nonmultichannel operation is limited to 38 MBps.
direct memory access (DMA) controller
The ’5421 includes two 6-channel direct memory access (DMA) controllers for performing data transfers
independent of the CPU, one for each subsystem. The DMA controller controls accesses to off-chip
program/data/IO and internal data/program memory. The primary function of the ’5421 DMA controller is to
provide code overlays and manage data transfers between on-chip memory, the peripherals, and off-chip
memory.
In the background of CPU operation,the ’5421 DMA allows movement of data between internal and external
program/data memory, and internal peripherals, such as the McBSPs and the HPI. Each subsystem has its own
independent DMA with six programmable channels, which allows for six different contexts for DMA operation.
The HPI has a dedicated auxiliary DMA channel. Figure 13 illustrates the memory map accessible by the DMA.
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