![](http://datasheet.mmic.net.cn/Maxim-Integrated-Products/DS34T102GN-_datasheet_97090/DS34T102GN-_106.png)
____________________________________________________ DS34T101, DS34T102, DS34T104, DS34T108
106 of 366
Interrupt Type
Interrupt Procedure
CW_bits_change
1. Clear the CW_bits_change bit in the
Intpend register by writing 1 to
it.
2
2
JB_underrun_Pn
1. Read the JBC_underrun bits in the
Intpend register to determine
which port(s) are indicating jitter buffer underrun.
2. Clear the set JBC_underrun bits in the
Intpend register by writing 1
to them.
3. Read the corresponding
JBC_underrun register(s) to determine
which buffers had underruns.
4. Clear the set bits in the
JBC_underrun register(s) by writing 1 to
them.
5. Service the underrun(s) as needed.
ETH_MAC
1. Clear the ETH_MAC bit in the
Intpend register by writing 1 to it.
of interrupts in the MAC (all bits are reset to 0 upon read).
3. Service the source(s) of the interrupt(s).
If a bit in the
Intpend register is set and that interrupt is then masked, the device generates an interrupt immediately
after the CPU clears the corresponding mask bit. To avoid this behavior, the CPU should clear the interrupt from
the
Intpend register before clearing the mask bit.
10.9.2 LIU, Framer and BERT Interrupts
when
GCR1.IPOR=1). The CPU first reads the
GTISR register to identify which LIU(s), Framer(s) or BERT(s) are
generating the interrupt request(s). For LIU interrupts, the CPU then reads the corresponding
LLSR register(s) to
identify the source of the interrupt(s). For BERT interrupts, the CPU reads the corresponding
BSRL register(s).
For framer interrupts, the CPU reads the framer’s interrupt information registers
(TIIR, RIIR) to further identify the
source of the interrupt(s). If
TIIR indicates interrupt(s), the CPU then reads the corresponding transmit latched
status register(s) to determine the source(s) of the interrupts. If
RIIR indicates interrupt(s), the CPU then reads the
corresponding receive latched status register(s) to determine the source(s) of the interrupts. The
TIIR and
RIIR bits
are real-time bits that clear after the corresponding interrupt(s) have been cleared, as long as no additional, un-
masked interrupt conditions are present in the associated latched status registers.
All latched status bits in the LIUs, framers and BERTs are cleared by the CPU writing 1 to the bit. Latched status
bits that have been masked via interrupt mask registers do not affect the bits in the framer interrupt information
registers. The Interrupt mask bits prevent individual latched status conditions from generating interrupts, but they
do not prevent the latched status bits from being set. Therefore, when servicing interrupts, the CPU should
consider the interrupt mask bits in order to exclude latched status bits for which interrupts are masked. This
architecture allows the CPU to periodically poll the latched status bits for non-interrupt conditions, while using only
one set of registers.