
XRT84L38
167
REV. 1.0.1
OCTAL T1/E1/J1 FRAMER
For a given Framer, the Block Interrupt Status Register presents the Interrupt Request status of each Interrupt
Block within the Framer. The Block Interrupt Status Register helps the
μ
P/
μ
C identify which Interrupt Block(s)
have 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 27
. Once the
μ
P/
μ
C 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 Framer IC further supports the Interrupt Block Hierarchy by providing the Block Interrupt Enable Register.
The bit-format of this register is identical to that for the Block Interrupt Status Register and is presented below.
The Block Interrupt Enable Register permits the user to individually enable or disable the interrupt requesting
capability of each of the "interrupt blocks" within the Framer. If a particular bit-field, within this register contains
the value "0"; then the corresponding functional block has been disabled from generating any interrupt
requests.
1.7.1
Configuring the Interrupt System, at the Framer Level
The XRT84L38 Framer IC permits the user to enable or disable each of the eight Framers for interrupt
generation. Further, the chip permits the user to make the following configuration selection.
1.
Whether the source-level Interrupt Status bits are Reset-upon-Read or Write-to-Clear.
2.
Whether or not an activated interrupt is automatically cleared.
1.7.1.1
Enabling/Disabling the Framer for Interrupt Generation
Each of the eight (8) Framers of the XRT84L38 Framer can be enabled or disabled for interrupt generation.
This selection is made by writing the appropriate “0” or “1” to bit 0 (INTRUP_EN) of the Interrupt Control
Register corresponding to that framer, (see
Table 29
).
T
ABLE
28: B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
R
EGISTER
320 B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(BIER) H
EX
A
DDRESS
: 0
X
nA, 0
X
01
B
IT
F
UNCTION
T
YPE
D
EFAULT
D
ESCRIPTION
-O
PERATION
7
SA6_ENB
R/W
0
SA6 interrupt enable
6
LBCODE_ENB
R/W
0
Loopback code interrupt enable
5
RXCLKLOSS
R/W
0
RxLineClk Loss Interrupt Enable
0 = Disables interrupt
1 = Enables interrupt
4
ONESEC_ENB
R/W
0
One Second Interrupt Enable
0 = Disables interrupt
1 = Enables Interrupt
3
HDLC_ENB
R/W
0
HDLC Block Interrupt Enable
0 = Disables all HDLC Block interrupts
1 = Enables HDLC Block (for interrupt generation) at the block level
2
SLIP_ENB
R/W
0
Slip Buffer Block Interrupt Enable
0 = Disables all Slip Buffer Block Interrupts
1 = Enables Slip Buffer Block at the block level
1
ALARM_ENB
R/W
0
Alarm & Error Block Interrupt Enable
0 = Disables all Alarm & Error Block interrupts
1 = Enables Alarm & Error block at the block level
0
T1/E1FRAME_ENB
R/W
0
T1/E1 Frame Block Enable
0 = Disables all Frame Block interrupts
1 = Enables the Frame Block at the block level