Datasheet

System Architecture
2-4 SHARC Audio EZ-Extender Manual
The analog audio interface consists of three AD1939 audio codec ICs
(referred to as “AD1939A”, “AD1939B”, and “AD1939C”), which use up
to six serial ports (SPORTs) of the processor. All of the clock and frame
sync signals of the processor are driven by the master AD1939 codec
(AD1939A).
The master codec can run in either Time-Division Multiplexed (TDM)
mode or Integrated Interchip Sound (I
2
S) mode at a 48 KHz, 96 KHz, or
192 KHz sample rate in both modes using only two serial ports. Codecs B
and C are connected to be slaves only and are hard-wired on the
EZ-Extender to run in dual-line TDM. Codecs B and C can run in con-
junction with codec A using six of the processor’s eight serial ports for
dual-line TDM operation at a 192 KHz sample rate. In all cases, the pro-
cessor is wired to be a slave, and the serial port clock and frame syncs are
generated by the master codec (AD1939A).
Each of the Audio EZ-Extender’s codecs is configured using the SPI port
of the processor. Each codec includes its own chip select pin.
The SHARC Audio EZ-Extender also is equipped with a 2-wire I
2
C serial
flash memory device (M24C02). The M24C02 memory can store up to
2 KB of data, which includes a section pre-programmed with board revi-
sion data (PCB revision, BOM revision, serial number, etc.) and allows
software to search for board-specific information at runtime. The flash
memory device is connected to the EZ-Board via DPI pins 7 and 8. The
address of the two-wire device can be modified using the DIP switch on
the Audio EZ-Extender; see “Memory Configuration Switch (SW19)” on
page 2-14 for more information.