Technical data

1.5.12 Special Mode Register
15 14 13 12 11 10 9 8 No. Initial value
MIIMODE Reserved FX_MOD
E
Reserved 18 000xH
7 6 5 4 3 2 1 0
PHY_MODE PHY_ADD
Table 35: Special Mode Register Overview
Bit position Bit name R/W Function
15:13 MIIMODE R/W MIIMODE
Selects different interface types between PHY and MAC.
MIIMODE MIIMODE selection
00b MII interface (initial value)
others Reserved
13 - R Reserved
Ignore on read access
12:11 - R/W Reserved
Write 0
b
; ignore on read access
10 FX_MODE R/W FX_MODE
Enables the 100BASE-FX mode
FX_MODE 100BASE-TX mode enable
0
b
FX_MODE disabled (initial value after hardware
reset)
1
b
FX_MODE enabled
Notes: 1. The initial value after a software reset of the PHYs, is
selected by the contents of the Pn_FX_MODE field in the PHY_CONFIG reg
ister.
2. When FX_MODE is set to 1
b
, the PHY_MODE field must be set to
either 011
b
or 010
b
. A consistent setting of both fields is required; otherwise
proper operation of the PHYs cannot be guaranteed.
9:8 - R/W Reserved
Write 0
b
; ignore on read access
Copyright © Siemens AG 2008. All rights reserved. Page 45 ERTEC 200 PHY
Technical data subject to change Version 1.0.0