PEB 2091
PEF 2091
Functional Description
3.8
Microprocessor Interface
Note 21: This Interface is only available in the microprocessor mode.
The parallel/serial microprocessor interface can be selected to be either of the
1. Siemens/Intel non-multiplexed bus type with control signals CS, WR, RD
2. Motorola type with control signals CS, R/W, DS
3. Siemens/Intel multiplexed address/data bus type with control
signals CS, WR, RD, ALE
4. Serial mode using control signals CDIN, CDOUT, CCLK and CS.
The selection is performed via pins ALE/CCLK and SMODE as follows:
Table 12
Microprocessor Interface Modes
ALE
0
SMODE
Siemens/Intel non-Mux
Motorola
x
x
0
1
1
Siemens/Intel Mux
Serial
edge
edge
The occurrence of an edge on ALE/CCLK, either positive or negative, at any time during
the operation immediately selects interface type 3 or 4. A return to one of the other
interface types is possible only if a hardware reset is issued.
The timing of the different microprocessor bus types is given in sections 8.7.1, page 269
for the parallel bus type and in section 8.7.2, page 273, for the serial bus type.
3.9
S/G Bit and BAC bit Control
Note 22: This chapter applies only in the µP-TE mode (see "Basic Operating
Mode", page 50).
If DCL = 1.536 MHz the IOM®-2 interface consists of three IOM®-2 channels (see
"Terminal Timing Mode", page 73). The last octet of an IOM®-2 frame includes the S/G
and the BAC bit. Either or both bits can be used in various applications including
• the D-channel arbitration in a PBX via an ELIC® on the line card
• the synchronization of a base station in wireless local loop applications
The S/G bit is always written and never read by the IEC-Q. Its value depends on the last
received EOC-command and on the status of the BAC bit. The processing mode for the
S/G bit is selected via bits SWST:BS, SWST:SGL and ADF:CBAC (see "ADF-Register",
page 219). A detailed operational description of the S/G bit control in all modes is
provided in "S/G Bit and BAC Bit Operations", page 198.
Semiconductor Group
90
Data Sheet 01.99
INFINEON [ Infineon ]
