10h–1Fh Register Map Detailed Description
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 523
1Ch: Cabletron LED Register (Shadow Register Selector = “00h”)
Reading from and writing to register 1Ch is through register 1Ch bits [15:10]. Bits [14:10] set the shadow of
register 1Ch, and bit 15 enables the writing of bits [9:0]. Setting bit 15 allows writing to bits [9:0] of register 1Ch.
To read register 1C shadow zzzzz, first set writes to register 1Ch with bit 15 = 0, and bits [14:10] to zzzzz. The
subsequent register read from register 1Ch contains the shadow zzzzz register value.
--------------------------------------------
PHY 0x1C Shadow 0x1 register read Procedure
--------------------------------------------
int value;
phy_write(0x1C, 0x0400); //switch to shadow 0x1
value = phy_read(0x1C);
return value;
--------------------------------------------
PHY 0x1C Shadow 0x2 register write Procedure
--------------------------------------------
int wdata;
phy_write(0x1C, 0x0800); //switch to shadow 0x2
phy_write(0x1C, wdata | 0x8800 );
Bit
Name
RW
Description
Default
15
WRITE ENABLE
RW
1 = write bits [9:0]
0 = read bits [9:0]
0
14:10 SHADOW REGISTER
SELECTOR
RW
Shadow Register Selector
00000 = shadow register 0 read/write select
00001 = shadow register 1 read/write select
...
11111 = shadow register 31 read/write select
00000
9:8
RESERVED
RW
Write as 0, ignore on read
-
