
XRT7234
E3 UNI FOR ATM
x r
PRELIMINARY
REV. P1.0.0
38
3.0 Microprocessor Interface Section and On-Chip Programmable Registers
The Microprocessor Interface section supports communication between the “l(fā)ocal” microprocessor (
μ
P) and the UNI
device. In particular, the Microprocessor Interface section supports the following operations between the local
microprocessor and the UNI.
The writing of configuration data into the UNI on-chip (addressable) registers.
The writing of “outbound” OAM cell data into the “Transmit OAM Cell” Buffer (within the UNI).
The writing of an “outbound” PMDL (Path Maintenance Data Link) message into the “Transmit LAPD Message” buffer
(within the UNI).
The UNI IC’s generation of an Interrupt Request to the
μ
P.
The
μ
’s servicing of the interrupt request from the UNI.
The monitoring of the UNI system’s “health” by periodically reading the on-chip Performance Monitor registers.
The reading of an “inbound” OAM cell data from the “Receive OAM Cell” buffer (within the UNI).
The reading of an “inbound” PMDL Message from the “Receive LAPD” Buffer (within the UNI).
Each of these operations (between the local microprocessor and the UNI) will be discussed in some detail,
throughout this data sheet.
Figure 5 presents a simple block diagram of the Microprocessor Interface Section, within the UNI device.
Figure 5. Simple Block Diagram of Microprocessor Interface block of UNI.
3.1 The Microprocessor Interface Signals
The UNI may be configured into a wide variety of different operating modes and have its performance monitored by
software through a standard (local “housekeeping”) microprocessor, using data, address and control signals.
Note:
This local “housekeeping” Microprocessor should not be confused with the ATM Layer Processor that interfaces
to the UNI via the Transmit and Receive Utopia Interface Blocks.
A[8:0]
WrB_RW
RdB_DS
CSB*
ALE_AS
Reset
IntB*
D[15:0]
Width16
MOTO
Rdy_Dtck
Microprocessor Interface
and
Programmable Registers