bt8970 Mindspeed Technologies, bt8970 Datasheet - Page 48

• Manufacturer Part Number: bt8970
• Description: Single-chip Hdsl Transceiver
• Manufacturer: Mindspeed Technologies

4.0 Register
0x05—IRQ Source Register (irq_source)
Independent read/write (zero only) interrupt flags, one for each of four internal sources. Each flag bit is set and
stays set when its corresponding source indicates that a valid interrupt condition exists. If unmasked, this event
will cause the IRQ output to be activated. Writing a logic zero to an interrupt flag whose underlying condition
no longer exists will cause the flag to be immediately cleared. Attempting to clear a flag whose underlying
condition still exists will not immediately clear the flag, but will allow it to remain set until the underlying
condition expires, at which time the flag will be cleared automatically. The clearing of an unmasked flag will
cause the IRQ output to return to an inactive state, if no other unmasked interrupt flags are set.
sync
high_felm
low_felm
low_snr
4-4
7
–
Sync Indication—Active when the sync detector is enabled and its accumulated equivalent
comparisons exceeds (greater than) the threshold value stored in the Scrambler Sync
Threshold Register [scr_sync_th; 0x2E].
Far-End Level Meter High Alarm—Active when the far-end level meter value exceeds (greater
than) the threshold stored in the Far-End High Alarm Threshold Registers
[far_end_high_alarm_th_low, far_end_high_alarm_th_high; 0x30–0x31].
Far-End Level Meter Low Alarm—Active when the far-end level meter value exceeds (less
than) the threshold stored in the Far-End Low Alarm Threshold Registers
[far_end_low_alarm_th_low, far_end_low_alarm_th_high; 0x32–0x33].
Signal-to-Noise Ratio Low Alarm—Active when the SNR Alarm meter value exceeds (greater
than) the threshold stored in the SNR Alarm Threshold Registers [snr_alarm_th_low,
snr_alarm_th_high; 0x34–0x35].
6
–
Preliminary Information/Conexant Proprietary and Confidential
5
–
4
–
Conexant
sync
3
high_felm
2
Single-Chip HDSL Transceiver
low_felm
1
low_snr
100101B
Bt8970
0