This PCB handles the network connectivity & USB support. Telnet control
(Ethernet to RS232 tunnelling) is also handled by this PCB.
IC102 (DM850 audio processor) does not have any internal boot code, upon
being powered, it starts the BFL (First level bootloader) from the FLASH
memory IC202 (S29GL064A90TFIR30). This then executes the BSL (second
level bootloader) which brings up the network support. The second level
bootloader then executes the application. The BFL should never need to be
updated and as such will not be included in the standard upgrading
application.
The FLASH memory is also used to store settings, such as the Arcam specific
Cardea keys & MAC address. Note: if the FLASH device is ever changed, it
is essential that the original MAC address be programmed into the unit so that
the user does not lose and internet radio stations/favourites groups.
The device also uses SDRAM (not until the BSL executes) – IC200
(IC42S16800-6T(G)).
Wifi connectivity is via an Edom module and plugs into CON300. Note: this
module is specific to this unit and cannot be substituted, spares must come
from Arcam.
Wired Ethernet uses IC400 (DM9161A MAC), L401 (TS6121C magnetics).
The Ethernet connector (CON400) does not have any link or act LEDs as
these were thought to be potentially annoying in an AV environment.
In addition to the SPDIF audio output, there analogue audio is generated from
NET MClk, NET BClk, NET WClk & NET Data0 using IC501 (CS4345 DAC).
IC500 (LM358AM op amp) buffers & filters the output of the DAC. The output
can then be muted under control of the DM850 (/MUTE) and then ground
balanced with IC502 (NJM2114 op amp).
The DM850 uses two switching regulators for generating the +3V3D
(REG600) and 1V8 (REG601). IC601 (SP6661 charge pump) generates the -
5V used by the ground balancing circuit – IC601 has a 4V7 zener regulator
circuit supplying it.
L119AY NETWORK
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