Serial Interface with Time Slot Assigner
7-90
MC68360 USER’S MANUAL
MOTOROLA
If its V-bit is set, TbPTR contains the address of the Tx entry currently active. The SI RAM
transmit address block in use is 192–255, and CROTa = 1 in SISTR.
7.8.5.6.3 SIRP When RDM = 10 (Two Static TDMs).
This is the simplest case, since each
pointer is continuously used and has only one function.
RaPTR contains the address of the RXa entry currently active.
RbPTR contains the address of the RXb entry currently active.
TaPTR contains the address of the TXa entry currently active.
TbPTR contains the address of the TXb entry currently active.
7.8.5.6.4 SIRP When RDM = 11 (Two Dynamic TDMs).
In this case, each pointer is con-
tinuously used, but points to different sections of the SI RAM, depending on whether
the pointer’s value is in the first half (0–15) or the second half (16–31).
RaPTR contains the address of the RXa entry currently active. If the pointer has a value
from 0–15, the current-route RAM is SI RAM address block 0–31, and CRORa = 0 in SIS-
TR. If the pointer has a value from 16–31, the current-route RAM is SI RAM address block
32–63, and CRORa = 1 in SISTR.
RbPTR contains the address of the RXb entry currently active. If the pointer has a value
from 0–15, the current route RAM is SI RAM address block 64–95, and CRORb = 0 in SIS-
TR. If the pointer has a value from 16–31, the current-route RAM is SI RAM address block
96–127, and CRORb = 1 in SISTR.
TaPTR contains the address of the TXa entry currently active. If the pointer has a value
from 0–15, the current route RAM is SI RAM address block 128–159, and CROTa = 0 in
SISTR. If the pointer has a value from 16–31, the current-route RAM is SI RAM address
block 160–191, and CROTa = 1 in SISTR.
TbPTR contains the address of the TXb entry currently active. If the pointer has a value
from 0–15, the current-route RAM is SI RAM address block 192–223, and CROTb = 0 in
SISTR. If the pointer has a value from 224–255, the current-route RAM is SI RAM address
block 160–191, and CROTb = 1 in SISTR.
7.8.6 SI IDL Interface Support
The IDL interface is a full-duplex ISDN interface used to connect a physical layer device to
the QUICC. The QUICC supports both the basic rate and the primary rate of the IDL bus. In
the basic rate of IDL, data on three channels, B1, B2, and D, is transferred in a 20-bit frame,
providing 160-kbps full-duplex bandwidth. The QUICC is an IDL slave device that is clocked
by the IDL bus master (physical layer device) and has separate receive and transmit sec-
tions. Because the QUICC can support two TDMs, it can actually support two independent
IDL buses using separate clocks and sync pulses as shown in Figure 7-31.