XRT72L53 Datasheet, PDF (51/467 Pages) Exar Corporation – THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L53
REV. P1.1.7
THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
áç
PRELIMINARY
FIGURE 24. SIMPLE BLOCK DIAGRAM OF THE MICROPROCESSOR INTERFACE BLOCK, WITHIN THE FRAMER IC
A(10:0)
WR_R/W
Rd_DS
CS
ALE_AS
Reset
Int
D[7:0]
MOTO
RDY_DTCK
Microprocessor
&
Programable Registers
2.2 THE MICROPROCESSOR INTERFACE BLOCK SIG-
NAL
The Framer IC may be configured into a wide variety
of different operating modes and have its perfor-
mance monitored by software through a standard (lo-
cal housekeeping) microprocessor, using data, ad-
dress and control signals.
The local µP configures the Framer IC (into a desired
operating mode) by writing data into specific address-
able, on-chip Read/Write registers, or on-chip RAM.
The microprocessor interface provides the signals
which are required for a general purpose micropro-
cessor to read or write data into these registers. The
Microprocessor Interface also supports polled and in-
terrupt driven environments. These interface signals
are described below in Table 2, Table 3, and Table 4.
The microprocessor interface can be configured to
operate in the Motorola Mode or in the Intel mode.
When the Microprocessor Interface is operating in the
Motorola mode, then some of the control signals
function in a manner as required by the Motorola
68000 family of microprocessors. Likewise, when the
Microprocessor Interface is operating in the Intel
Mode, then some of these Control Signals function in
a manner as required by the Intel 80xx family of mi-
croprocessors.
Table 2 lists and describes those Microprocessor In-
terface signals whose role is constant across the two
modes. Table 3 describes the role of some of these
signals when the Microprocessor Interface is operat-
ing in the Intel Mode. Likewise, Table 4 describes the
role of these signals when the Microprocessor Inter-
face is operating in the Motorola Mode.
51