PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 98

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

Semiconductor Group
Note 28: The microprocessor interface provides almost unlimited access
4.1.1
Setting SWST:B1 (B2) to "1" enables the microprocessor to access B1 (B2)-channel
data between IOM
Eight registers (see Table 14) handle the transfer of data from IOM
the µP to IOM
Table 14
Register
WB1U
RB1U
WB1I
RB1I
WB2U
RB2U
WB2I
RB2I
For more informations about these registers, refer to "B-Channel Access Registers",
page 221. Every time B-channel bytes arrive, an interrupt ISTA:B1 or ISTA:B2
respectively is created. It is cleared after the corresponding registers have been read.
ISTA:B1 is cleared after RB1U and RB1I have been read. ISTA:B2 is cleared after RB2I
and RB2U have been read. After an interrupt the data in RB1U and RB1I is stable for
125µs. For more informations, refer to "Interrupt Structure", page 209.
possibilities to the active IOM
is that all actions described in this document involving the active
channel of the IOM
channels) can be also performed using the PI.
In the IOM
interface is possible even if the IOM
pin DIN should be clamped to ’1’.
In the IOM
are needed for internal data synchronization reasons. If pin DIN is not
used, it should be clamped to ’1’. If pin DOUT is not used it should be
left open.
B-Channel Access
®
B1/B2-Channel Data Registers
-2, from the µP to transceiver core and from transceiver core to the µP:
Function
write B1-channel data to transceiver core
read B1-channel data from transceiver core
write B1-channel data to IOM
read B1-channel data from IOM
write B2-channel data to transceiver core
read B2-channel data from transceiver core
write B2-channel data to IOM
read B2-channel data from IOM
®
-2 and the transceiver core.
®
®
-2 Slave mode the IOM
-2 Master mode proper function using the microprocessor
®
-2 interface or parts of it (e.g. B, D, Monitor and C/I
98
®
-2 channel. One important consequence
®
®
-2
-2
®
®
®
®
-2 clocks can not be omitted. They
-2
-2
-2 interface is omitted. In this case
Operational Description
®
-2 to the µP, from
Data Sheet 01.99
PEB 2091
PEF 2091