RS8973 Mindspeed Technologies, RS8973 Datasheet - Page 56

• Manufacturer Part Number: RS8973
• Description: Single-chip Sdsl/hdsl Transceiver
• Manufacturer: Mindspeed Technologies

3.0 Registers
3.3 Register Description
Independent read/write (zero only) interrupt flags, one for each of eight internal timers. Each flag bit is set and
stays set when its corresponding timer value transitions from 1 to 0. If unmasked, this event causes the IRQ
output to be activated. Flags are cleared by writing them with a logical 0 value. Once a flag is cleared, a
steady-state timer value of 0 does not reassert the flag. Clearing an unmasked flag causes the IRQ output to
return to the inactive state, if no other unmasked interrupt flags are set.
t4
t3
snr
meter
sut4
sut3
sut2
sut1
Independent read/write (0 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
causes the IRQ output to be activated. Writing a logical 0 to an interrupt flag whose underlying condition no
longer exists causes the flag to be immediately cleared. Attempting to clear a flag whose underlying condition
still exists does not immediately clear the flag, but allows it to remain set until the underlying condition expires,
at which time the flag is cleared automatically. The clearing of an unmasked flag causes the IRQ output to return
to an inactive state, if no other unmasked interrupt flags are set.
sync
high_felm
low_felm
low_snr
3-10
0x04—Timer Source Register (timer_source)
0x05—IRQ Source Register (irq_source)
—
t4
7
7
General Purpose Timer 4
General Purpose Timer 3
SNR Alarm Timer
Meter Timer
Startup Timer 4
Startup Timer 3
Startup Timer 2
Startup Timer 1
Sync Indication—Active when the sync detector is enabled and its accumulated equivalent
comparison is 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 is 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 is 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 is greater than
the threshold stored in the SNR Alarm Threshold Registers [snr_alarm_th_low,
snr_alarm_th_high; 0x34–0x35].
—
t3
6
6
snr
—
5
5
Preliminary Information
meter
—
4
4
Conexant
sut4
sync
3
3
high_felm
sut3
Single-Chip SDSL/HDSL Transceiver
2
2
low_felm
sut2
1
1
N8973DSD
low_snr
RS8973
sut1
0
0