MM516
User's Manual
32
Revision 1.4 7-8-2011
Hardware Description Manual
5.4.5 GCI Interface
BlueCore 5 chip is compatible with the GCI, a standard synchronous 2B+D ISDN timing interface. The two
64kbits/s B channels can be accessed when this mode is configured.
Figure 18
GCI Interface
Figure 17
GCI Interface
The start of frame is indicated by the rising edge of PCM_SYNC and runs at 8kHz. With BlueCore 5 chip in Slave
mode, the frequency of PCM_CLK can be up to 4.096MHz.
5.4.6 Slots and Sample Formats
BlueCore 5 chip can receive and transmit on any selection of the first four slots following each sync pulse. Slot
durations can be either 8 or 16 clock cycles. Durations of 8 clock cycles may only be used with 8-bit sample formats.
Durations of 16 clocks may be used with 8-bit, 13-bit or 16-bit sample formats.
BlueCore 5 chip supports 13-bit linear, 16-bit linear and 8-bit -law or A-law sample formats. The sample rate is
8ksamples/s. The bit order may be little or big endian. When 16-bit slots are used, the 3 or 8 unused bits in each
slot may be filled with sign extension, padded with zeros or a programmable 3-bit audio attenuation compatible with
some Motorola codecs.