AM79C978 Advanced Micro Devices, AM79C978 Datasheet - Page 185

• Manufacturer Part Number: AM79C978
• Description: Single-Chip 1/10 Mbps PCI Home Networking Controller
• Manufacturer: Advanced Micro Devices

HPR24: HomePNA PHY Noise Control 2 (Register
24)
HPR25: HomePNA PHY Noise Statistics (Register
25)
Bits
15:8
Bits
15:8
7:0
7:0
PHY_NOISE_CTRL2
Noise Attack
Reserved
PHY_NOISE_STAT
Noise Level
Peak Level
Mnemonic
Mnemonic
Table 57. HPR25: HomePNA PHY Noise Statistics (Register 25)
Table 56. HPR24: HomePNA PHY Noise Control 2 (Register 24)
Sets the attack characteristics of the NOISE
algorithm. High nibble sets number of noise
events needed to raise the NOISE level
immediately, while the low nibble is the number
of noise events needed to raise the level at the
end of an 870 ms period.
Reads will produce undefined results
This is the digital value of the
SLICE_LVL_NOISE output. It is effectively a
measure of the noise level on the wire and
tracks noise by counting the number of false
triggers of the NOISE comparator in an 800 ms
window. When auto-adaptation is enabled (bit 5
of the PHY_Control Register is false), this
register is updated with the current NOISE
count every 50 ns. When adaptation is
disabled, this register may be written to and is
used to generate both the SLICE_LVL_NOISE
and SLICE_LVL_DATA signals.
This is a measurement of the peak level of the
last valid (non-collision) AID received.
Am79C978
Description
Description
Read/
Read/
Write
Write
R/W
R/W
R/W
R
Default
Default
Hex
Hex
FF
03
F4
Reset
Reset
Soft
Soft
FF
03
F4
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