XRT94L33
xr
Rev.1.2.0.
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
140
Each of the “Operation Block Interrupt Status” Registers presents the “interrupt-request” status of each
functional block, within the chip. The purpose of these two registers is to help the
C/P identify which
functional block(s) has requested the interrupt. Whichever bit(s) are asserted, in this register, identifies which
block(s) have experienced an “interrupt-generating” condition as presented in Table _. Once the
C/P has
read this register, it can determine which “branch” within the interrupt service routine that it must follow in
order to properly service this interrupt.
The XRT94L33 ATM UNI/PPP IC further supports the Operational Block hierarchy by providing the Operation
Block Interrupt Enable Register – Bytes 1 and 0. The bit format of these two registers are identical to that for
the Operation Block Interrupt Status Registers – Bytes 1 and 0, and are presented below for the sake of
completeness.
Operation Block Interrupt Enable Register – Byte 1 (Address Location = 0x0116)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Op Control
Block
Interrupt
Enable
DS3/E3
Mapper
Block
Interrupt
Enable
Unused
Receive
STS-1 TOH
Processor
Block
Interrupt
Enable
Receive
STS-1 POH
Processor
Block
Interrupt
Enable
DS3/E3
Framer
Block
Interrupt
Enable
Receive
Line
Interface
Block
Interrupt
Enable
Unused
R/W
R/O
0
Operation Block Interrupt Enable Register – Byte 0 (Address Location = 0x0117)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Receive
ATM Cell
Processor
Block
Interrupt
Enable
Receive
STS-3 TOH
Processor
Block
Interrupt
Enable
Receive
SONET/
STS-3c
POH
Processor
Block
Interrupt
Enable
Receive
PPP
Processor
Block
Interrupt
Enable
Transmit
ATM Cell
Processor
Block
Interrupt
Enable
Unused
Transmit
PPP
Processor
Block
Interrupt
Enable
R/W
R/O
R/W
0
These Operation Block Interrupt Enable registers permit the user to individually enable or disable the interrupt
requesting capability of the functional blocks within the XRT94L33. If a particular bit-field, within this register
contains the value “0”, then the corresponding functional block has been disabled for generating any interrupt
requests. Conversely, if that bit-field contains the value “1”; then the corresponding functional block has been
enabled for interrupt generation (e.g., those potential interrupts, within the “enabled functional block” that are
enabled at the source level are now enabled). The user should be aware of the fact that each functional
block, within the XRT94L33 contains multiple potential interrupt sources. Each of these lower level interrupt
sources contain their own set of interrupt enable bits and interrupt status bits, existing in various on-chip
registers.