pef82902 Infineon Technologies Corporation, pef82902 Datasheet - Page 36

• Manufacturer Part Number: pef82902
• Description: 4b3t Second Generation Modular Isdn Nt Intelligent Extended
• Manufacturer: Infineon Technologies Corporation

PEF 81902
Functional Description
â
A read/write access to the T-SMINT
IX registers can be done in multiplexed or non-
multiplexed mode.
In non-multiplexed mode the register address must be applied to the address bus (A0-
A6) for the data access via the data bus (D0-D7).
In multiplexed mode the address on the address bus (AD0-AD7) is latched in by ALE
before a read/write access via the address/data bus is performed.
â
The T-SMINT
IX provides two different ways to address the register contents which can
be selected with the AMOD bit in the MODE2 register. The address mode after reset is
the indirect address mode (AMOD = ’0’). Reprogramming into the direct address mode
(AMOD = ’1’) has to take place in the indirect address mode.
Figure 8
illustrates both
register addressing modes.
Direct address mode (AMOD = ’1’): The register address to be read or written is directly
set in the way described above.
Indirect address mode (AMOD = ’0’):
• non-muxed: only the LSB of the address bus (A0)
• muxed: only the LSB of the address-data bus (AD0)
gets evaluated to address a virtual ADDRESS (0
) and a virtual DATA (1
) register.
H
H
Every access to a target register consists of:
• a write access (muxed or non-muxed) to ADDRESS to store the target register´s
address, as well as
• a read access (muxed or non-muxed) from DATA to read from the target register or
• a write access (muxed or non-muxed) to DATA to write to the target register
Data Sheet
22
2001-11-12