XRT94L33IB-L Exar Corporation, XRT94L33IB-L Datasheet - Page 134

• Manufacturer Part Number: XRT94L33IB-L
• Description: IC MAPPER DS3/E3/STS-1 504TBGA
• Manufacturer: Exar Corporation

Specifications of XRT94L33IB-L

• Applications: Network Switches
• Interface: Bus
• Voltage - Supply: 3.14 V ~ 3.47 V
• Package / Case: 504-LBGA
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XRT94L33
Rev.1.2.0.
Figure 7 Illustration of the Behavior of the Microprocessor Interface signal, during a “Motorola-type”
Programmed I/O Write Operation
1.4
The XRT94L33 is equipped with a sophisticated Interrupt Servicing Structure.
includes an Interrupt Request output pin, (INT*), numerous Interrupt Enable Registers and numerous Interrupt
Status Registers.
hierarchy. The top level is at the “Operational block level”. The second level is at the “Functional Block” level
(e.g., the Operation Control Block, Receive ATM Cell Processor Block, Receive PPP Processor Block, the
Receive STS-3 TOH Processor Block, the Receive STS-3c/SONET POH Processor Block).
hierarchical level is at the individual interrupt or “source” level. Each hierarchical level consists of a complete
set of Interrupt Status Registers/bits and Interrupt Enable Registers/bits, as will be discussed below.
Most of the functional blocks within the XRT94L33 are capable of generating Interrupt Requests to the µC/µP.
The XRT94L33 Interrupt Structure has been carefully designed to allow the user to quickly determine the
exact source of the interrupt (with a minimum number of read operations, and, in-turn, minimal latency) which
will aid the µC/µP in determining the appropriate interrupt service routine to call up in order to either eliminate,
or properly respond to the condition(s) causing the interrupt.
Table 6 lists all of the possible conditions that can generate interrupts in each functional block of the
XRT94L33.
ALE_AS
WRB_RW
RDB_DS
Rdy _ Dtck
D[7:0]
A[14:0]
CS*
INTERRUPT STRUCTURE WITHIN THE XRT94L33 ATM UNI/PPP IC
The Interrupt Servicing Structure, within the XRT94L33 IC contains three levels of
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
Address of Target Register
Data to be Written
134
This Interrupt Structure
xr
The lower