The SG3 board allows up to three simultaneous communications when used in combination with the FCU and optional G3 boards. The NCU is on the same board as the common SG-3 board. This makes the total board structure smaller. But, the specifications of the SG3 board do not change.
NCCP (New Communication Control Processor)
- Controls the SG3 board.
 - CPU (RU30)
 - DPRAM (Dual Port RAM): Handshaking with the FCU is done through this block.
 - DMA controller
 - JBIG
 - DSP V34 modem (RL5T892): Includes the DTMF Receiver function
 - DCR for MH, MR, MMR, and JBIG compression and decompression
 
FROM
- 1Mbyte flash ROM for SG3 software storage and modem software storage
 
SDRAM
- 4Mbyte DRAM shared between ECM buffer, line buffer, and working memory
 
AFE (Analog Front End)
- Analog processing
 
CODEC (COder-DECoder)
- A/D & D/A conversions for modem
 
REG
- Generates +3.3 V from the +5V from the FCU