AM79C978 Advanced Micro Devices, AM79C978 Datasheet - Page 184

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

HPR20 and HPR21: HomePNA PHY RxCOMM
(Registers 20 and 21)
The 32-bit received data field to be used for out-of-
band communication between PHY management enti-
ties. No protocol for out-of-band management has
been defined. Accessing the low word of the register is
sufficient to ensure that subsequently received packets
will not over-write the register contents. A non-null re-
HPR22: HomePNA PHY AID (Register 22)
The PHY’s AID address is used for collision detection.
Unless bit 7 of the CONTROL register is set, the PHY
is assured to select a unique AID address. Addresses
HPR23: HomePNA PHY Noise Control (Register 23)
184
14-15
Bits
15:8
Bits
15:8
7:0
7:0
Hex
PHY_AID
PHY_AID
Noise Events
PHY_NOISE_CTRL1
Noise Floor
Noise Ceiling
PHY_RX_COMM (4)
Table 53. HPR20 and HPR21: HomePNA PHY RxCOMM (Registers 20 and 21)
Mnemonic
Mnemonic
Mnemonic
Table 55. HPR23: HomePNA PHY Noise Control (Register 23)
Table 54. HPR22: HomePNA PHY AID (Register 22)
The Address ID of this PHY
If PHY_Control Disable AID Negotiation is not
set then writes to this bit will have no effect.
An 8-bit counter that records the number of
noise events detected. Overflows are held as
FFh. Can be cleared by setting bit 6 of the
control register.
The minimum value of the NOISE
measurement.
The maximum value if the NOISE
measurement. If it is exceeded, NOISE is reset
to the FLOOR.
The 32-bit preamble received on the
HomePNA PHY. Register 14 contains the high
word and Register 15 the low word.
Am79C978
Description
Description
Description
ceived PCOM will set the RxPCOM Valid bit of the
Event Status Register (Register HPR26). Accessing
the high word of the register clears this bit and allows
over-writing of the register by subsequent received
packets.
above EFh are reserved. Address FFh is defined to in-
dicate a remote command.
Read/
Read/
Write
Write
Read/
Write
R/W
R/W
R/W
R/W
R
Default
Default
Default
All 0s
Hex
Hex
Hex
FF
00
00
03
Reset
Reset
Reset
All 0s
Soft
Soft
Soft
FF
00
00
03