PRELIMINARY

16

PRELIMINARY

Rev F

CPC5750

Although the IOM-2 specification provides for two digitized voice time slots per sub-frame, the CPC5750 only uses the

B1 time slot. This allows for a total of eight available time slots when operating in the GCI Mode.

Selection of the sub-frame is not a provisioning option. It is done by applying the appropriate logic levels at pins:

SCLK, SDO, and SFSEL. See Section 6 IOM-2 (GCI) Interface beginning on page 23 and Table 4 on page 23

for more details.

Table 2:

PCLK Frequencies and Available PCM Time Slots

3.3 Hardware Configuration For Transmission Mode Selection

To ensure correct initialization of the CPC5750 following a Power Up or Reset event, the appropriate inputs must be

properly conditioned.

PCM Mode: SDI = 1 and CS = x

GCI Mode: SDI = 0 and CS = x;

Also, the sub-frame selection using SCLK, SDO, and SFSEL must be made at this time.

Failure to condition and hold these inputs at the appropriate logic level for the specified duration during Power Up or

Reset will require a Reset to re-initialize the device.

While the input CS may be conditioned to configure the CPC5750 for the desire companding method, this can be

modified via provisioning once the part becomes active.

Special Notes:

1) SDI and CS are not used in normal operation of the GCI Mode, therefore it is recommended that these

unused inputs be fixed to a stable logic level.

2) For the PCM Mode, SFSEL is an unused input and should be fixed to a stable logic level.

Frequency

Available PCM Time Slots

CPB = 0

(1 Clock per bit)

Available PCM Time Slots

CPB = 1

(2 Clocks per bit)

GCI Frequency

512kHz

84

No

1.024MHz

16

8

No

1.536MHz

24

12

No

2.048MHz

32

16

Yes: 1 Clock per bit

3.072MHz

48

24

No

4.096MHz

64

32

Yes: 2 Clocks per bit

6.144MHz

96

48

No

8.192MHz

128

64

No