Data Sheet

Bluegiga Technologies Oy
Page 30 of 44
Figure 21: GCI Interface
The start of frame is indicated by the rising edge of PCM_SYNC and runs at 8kHz. With WT41-E in Slave
mode, the frequency of PCM_CLK can be up to 4.096MHz.
9.6 Slots and Sample Formats
WT41-E 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.
WT41-E 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.