XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
3.0 MICROPROCESSOR INTERFACE BLOCK
REV. 1.0.1
The Microprocessor Interface section supports communication between the local microprocessor (µP) and the
Framer/LIU combo. The XRT86L30 supports an Intel asynchronous interface, Motorola 68K asynchronous,
and a Motorola Power PC interface. The microprocessor interface is selected by the state of the PTYPE[2:0]
input pins. Selecting the microprocessor interface is shown in Table 2.
TABLE 2: SELECTING THE
M
ICROPROCESSOR
INTERFACE
MODE
PTYPE[2:0]
M
ICROPROCESSOR M
ODE
0h (000)
Intel 68HC11, 8051, 80C188
(Asynchronous)
1h (001)
7h (111)
Motorola 68K (Asynchronous)
Motorola MPC8260, MPC860
Power PC (Synchronous)
The XRT86L30 uses multipurpose pins to configure the device appropriately. The local µP configures the
Framer/LIU by writing data into specific addressable, on-chip Read/Write registers. The microprocessor
interface provides the signals which are required for a general purpose microprocessor to read or write data
into these registers. The microprocessor interface also supports polled and interrupt driven environments. A
simplified block diagram of the microprocessor is shown in Figure 2.
FIGURE 2. SIMPLIFIED
B
LOCK
DIAGRAM OF THE
M
ICROPROCESSOR
INTERFACE BLOCK
CS
WR
RD
ALE
ADDR[11:0]
DATA[7:0]
µProcessor
Interface
PCLK
PTYPE [2:0]
Reset
DBEN
RDY
BLAST
INT
REQ[1:0]
ACK[1:0]
3.0.1
The Microprocessor Interface Block Signals
The XRT86L30 may be configured into different operating modes and have its performance monitored by
software through a standard microprocessor using data, address and control signals. These interface signals
are described below in Table 3, Table 4, and Table 5. The microprocessor interface can be configured to
operate in Intel mode or Motorola mode. When the microprocessor interface is operating in Intel mode, some
of the control signals function in a manner required by the Intel 80xx family of microprocessors. Likewise, when
the microprocessor interface is operating in Motorola mode, then these control signals function in a manner as
required by the Motorola Power PC family of microprocessors. (For using a Motorola 68K asynchronous
processor, see Figure 5 and Table 8) Table 3 lists and describes those microprocessor interface signals
whose role is constant across the two modes. Table 4 describes the role of some of these signals when the
microprocessor interface is operating in the Intel mode. Likewise, Table 5 describes the role of these signals
when the microprocessor interface is operating in the Motorola mode.
21
EXAR [ EXAR CORPORATION ]
