
MT9071
Preliminary Information
54
7.0
MT9071 Access and Control
7.1
Quad Transceiver Organization
The MT9071 contains 4 independent transceivers, referred to as transceiver 0 to transceiver 3. Each
transceiver has its own unique pins and unique addressing. In 8.192Mb/s mode, transceivers 0 to 3 are
grouped together on one ST-BUS stream. In addition, all 4 transceivers can be addressed together for write
operations by enabling the upper most address bit (A11).
7.2
Processor Interface (A11-A0, D15-D0, IM, DS, R/W, CS, IRQ, Pins)
The control and status of the MT9071 is achieved through a non-multiplexed parallel microprocessor port
capable of accommodating 12 address bits and 16 data bits. The parallel port may be configured for Motorola
style control signals (by setting pin IM low) or Intel style control signals (by setting pin IM high).
7.2.1
Transceiver and Register Access
The controlling microprocessor gains access to specific registers in the MT9071through a one step process.
The upper four address bits (A11-A8) access either a particular transceiver, a common write operation for all
four transceivers, or a global register group.
The middle four address bits (A7-A4) access a particular register group (i.e. Control, Status, Interrupt Mask
etc.).
The lower four address bits (A3-A0) access a particular register (i.e. CAS Control, Phase Status etc.).
See Table 11 - Tranceiver and Register Access.
For microprocessors with read/write cycles less than 165ns, a wait state is required. See Figure 35 - Motorola
Microprocessor Read Timing, Figure 36 - Motorola Microprocessor Write Timing, Figure 37 - Intel
Microprocessor Read Timing, and Figure 38 - Intel Microprocessor Write Timing for detailed timing
requirements.
Through out this document, the upper four address bits (A11-A8) are referred to as Y, (where Y indicates any
hex number between 0 and F). For detailed register descriptions, refer to the following sections:
Section 19.0 T1 & E1 Transceiver Address Space
Section 20.0 T1 & E1 Transceiver Registers Bit Summaries
Section 21.0 T1 & E1 Transceiver Registers Bit Functions.
Address
A
11
,A
10
,A
9
,A
8
A
7
,A
6
,A
5
A
4
A
3
,A
2
,A
1
,A
0
0 - Selects Transceiver 0
1 - Selects Transceiver 1
2 - Selects Transceiver 2
3 - Selects Transceiver 3
8 - Selects an all Tranceivers Write
9 - Selects a Global Register Group
Selects the register group (i.e.
Control, Status, Interrupt Mask
etc.)
Selects the particular register in the
register group (i.e. CAS Control,
Phase Status etc.)
Table 11 - Tranceiver and Register Access