Texas Instruments C5535 DSPShield, Справочник по аппаратуре

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C5535 DSPShield H/W Reference Manual Version 0.1
In Collaboration with Stanford University
page 28
6.5.2 Arduino Slave/C5535 DSP Master
This is a possible communication link between the Arduino and the C5535 DSP. In this
configuration, DSP_SPI_EN should be programmed to a “1” and SPI_RX_SEL should be
set to a “0”. The former turns on the TXB0104 buffer and the latter routes the Arduino
MISO pin on the connector to the C5535 DSP’s SPI RX input. The C5535 DSP’s SPI
Chip Select 0 (CS0) signal is routed to the Arduino SS chip select pin. See Figure 10b.
6.5.3 Arduino Isolated/C5535 DSP Master
This configuration allows the C5535 DSP to be the sole Master of the Arduino SPI
interface. DSP_SPI_EN should be programmed with a “1” and SPI_RX_SEL should be
programmed with a “0”. The Arudino uC SPI pins should be tri-stated either by keeping
the Arduino in reset or programming its SPI pins as inputs. See Figure 10c.
7 Resistor Multiplexing Configurations
The DSPShield has a number of multiplexing options that are controlled by resistors. The
previous sections have described some of the default configurations and possible
alternatives as well as control signals that can override them. Table 14 lists all the resistor
combinations and their functions. The defaults describe the configuration on power up
and after a manual reset.
Function Resistors Description
Input to C5535 USB_MXI
pin R1, R53 Default: USB_MXI = 12MHz External Oscillator
R1=DNI, R53=0 Ohm
USB_MXI = GND
R1=0 Ohm , R53=DNI
Ground 32.738 KHz Crystal
Casing R5, R7 Default: Crystal Case not grounded.
R5=DNI, R7=DNI
Crystal Case grounded.
R5=0 Ohm, R7=0 Ohm
C5535 System Clock
Generator Source R8, R9,
R10, R59 Default: Source from CLKIN pin (12MHz)
R8=DNI, R9=10K Ohm, R10=DNI, R59=0 Ohm
Source from 32.768KHz Crystal
R8=0 Ohm, R9=DNI, R10=0 Ohm, R59=DNI
Input to C5535 SPI RX pin R18, R166 Default: Source from Arduino Connector MISO
R18=10K Ohm, R166=DNI
Source from DSP_Expansion Connector
R18=DNI, R166=10K Ohm
C5535 Core Voltage Source R25, R26,
R27, R28 Default: Source from C5535 internal LDO.
R25=DNI, R26=0 Ohm, R27=0 Ohm, R28=DNI
Source from external LDO.