Evaluation Board User Guide
UG-072
Rev. A | Page 7 of 20
IC FUNCTIONS
Table 4 explains the function of each IC on the evaluation
board. The Lattice CPLD (U2) is only used for routing signals
on the board and performs no decoding or signal conditioning.
Table 4. IC Functions
Reference
Designator
Function
U1
ADAU1401A SigmaDSP audio processor
U2
Lattice M4A3-64/32 CPLD for signal routing
U3
AD8608
quad op amp for analog audio output
buffering
U4
CS8416 S/PDIF receiver
U5
74LVC541 for buffering serial output signals
U6
CS8406 S/PDIF transmitter
U8
ADP3336-3
regulator—3.3 V analog supply
U10
ADM811RART
reset generator
U11
Unused
U12
74LVC1G240 inverter
U14
Self-boot EEPROM: 32 kB × 8 (256 kB)
U18
Unused
U19
Unused
U20
Unused
LED FUNCTIONS
D11 indicates that the 3.3 V supply is present through an
external supply.
RESET
The evaluation board can be reset with a push-button switch,
S1. This active-low reset signal is debounced by the
ADM811
(U10). This reset signal affects the ADAU1401A and S/PDIF
receiver and transmitter. The board may also be reset by
disconnecting the power. After reset, the ADAU1401A does not
pass audio, and a control port write has to be performed so that
signals are output again.
SELF-BOOT
The self-boot function of the ADAU1401A can be set up on the
evaluation board. This allows the ADAU1401A to boot itself
from EEPROM U14 when it is brought out of reset. The
ADAU1401A is the master on the I
2
C bus during the self-boot
operation; however, another bus master device may take control
afterwards.
The first step in setting up self-boot mode is to load a program
from SigmaStudio into the EEPROM. This is done by using the
Load latest compilation to EEPROM
function found by right-
clicking on the IC in the
Hardware Configuration
window.
This should be done while the S3-1 self-boot switch is set low
(right). Note that the jumper should not be on LK7 for this
operation because the EEPROM cannot be write-protected.
After the program is saved, Switch S3-1 can be set high (left),
which sets the ADAU1401A into self-boot mode the next time
it is powered on or reset.
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
