2-40

Figure 8 - GCI/ST-BUS Interface

PCM

Streams

GCI CLK

(4.096 MHz)

GCI Frame Pulse

STo0

STi0

C4i

F0i

F0o

STi1

STo1

STo

STi

C4i

F0i

MT8982 MiniDx

Mitel Basic Rate

Phone Components

ST-BUS Frame Pulse

MT8982. Therefore, to connect GCI channel B1 to

ST-BUS

channel

B1,

the

MT8982

must

be

programmed to connect channel 5 to channel 2. The

five channel offset ensures that all four basic rate

channels will be switched together within one frame

period, regardless which direction the data is being

switched.

The five channel offset for GCI channels is required

even in GCI to GCI switching systems. For example,

to switch GCI channel B1 to GCI channel B2, the

MT8982 must be programmed to connect channel 5

to channel 6.

Figure 9 - ST-BUS/GCI Timing with ST-BUS as Master

Figure 10 - ST-BUS/GCI Timing with GCI as Master

Figure 11 - Switching GCI and ST-BUS Basic Rate Access Channels

Channel 0

Channel 4

Channel 5

F0i

C4i

F0o

Channel 0

Channel 4

Channel 5

F0i

C4i

F0o

ST-BUS

GCI

CH0

CH1

CH2

CH3

D

C

M

D and C/I

- ST-BUS and MiniDx Channels

CH0(5)

CH1(6)

CH2(7)

CH3(8)

- GCI (MiniDx) Channels