Cirrus Logic CDB5484U - Manual (Page 9)

CDB5484U
DS919DB5 9
1.4 Digital Section
The digital section contains the microcontroller, USB interface, LCD, optical isolation, JTAG header, reset
circuitry, and external interface headers (J17 and J19). The microcontroller interfaces the UART or SPI of
the CS5484 with the USB connection to the PC, enabling the GUI software to access all of the CS5484
registers and functions.
1.4.1 Serial Port Selection
Communication to the CS5484 is provided through two serial port options: UART or SPI. It is necessary
to establish communication with the MCU before establishing a serial port communication protocol with
the CS5484 (see Figure 5).
Figure 5. MCU Connection Window
For UART communication, place the SSEL jumper to the UART position via J16, and select UART in the
serial port selection window. To enable SPI communications, place the SSEL jumper to the SPI position
via J16, and select SPI in the serial port selection window. Table 3 provides the serial communication op-
tions on the CDB5484U board.
Table 3. Serial Communication Options
UA
SP
Low s
UA
(4800 Ba
ART
PI
speed
ART
aud Max)
J16
Ƒ UART
ż SSEL
ż SPI
(default)
Ƒ UART
ż SSEL
ż SPI
Ƒ UART
ż SSEL
ż SPI
Ƒ
ż
ż
(d
Ƒ
ż
ż
Ƒ
ż
ż
J18
Ƒ OPTO
ż RX
ż DIGITAL
default)
Ƒ OPTO
ż RX
ż DIGITAL
Ƒ OPTO
ż RX
ż DIGITAL
J
Ƒ O
ż T
ż D
(defa
Ƒ O
ż T
ż D
Ƒ O
ż T
ż D
J20
OPTO
TX
DIGITAL
ault)
OPTO
TX
DIGITAL
OPTO
TX
DIGITAL
J50
Ƒ VDDA
ż EN2
ż GND
(default)
Ƒ VDDA
ż EN2
ż GND
Ƒ VDDA
ż EN2
ż GND
A
)
A
A