
58
Agere Systems Inc.
Data Sheet
May 2001
and Packet Payload Engine
Ambassador T8110 PCI-Based H.100/H.110 Switch
6 Operating Control and Status
(continued)
6.2.2 System Status
6.2.3 Clock Fallback Status Register
The upper nibble provides status indicators for clock fallback. FBFOB indicates whether the circuit is in a clock fall-
back state. FBSOP indicates which of five possible states the circuit is in; see Section 7.7.1 on page 82 for more
details.
The lower nibble provides status indicators related to the X and Y clock register set active/inactive assignments.
XYSOB indicates which of the clock register sets is active. The remaining bits indicate a pending status for
GO_CLOCKS, CLEAR_FALLBACK, and FORCE_FALLBACK commands issued (via the fallback control register,
0x00108), which are waiting for a frame sync.
Table 38. Fallback and Failsafe Status Register
6.2.4 PLL and Switching Status Register
The upper 6 bits provide APLL1, DPLL1, and DPLL2 lock status. For more details, see Section 7 on page 62. The
lower 2 bits provide memory status as follows: CMROB is an indicator for the connection memory actively reset-
ting; see Section 14.2.1.1 on page 146. DMPOB indicates the active data page used for double-buffered standard
switching; see Section 14.2.1.2 on page 148.
Byte
Address
Register Name
Bit(s) Mnemonic Value
Function
0x00124 Status 4, Clock Fallback
Status
7
FBFOB
0
1
Indicates not in fallback/failsafe state (default).
Indicates fallback/failsafe state.
Fallback state = INITIAL (default).
Fallback state = PRIMARY.
Fallback state = TO_PRIMARY.
Fallback state = SECONDARY.
Fallback state = TO_SECONDARY.
Failsafe state = FS_1.
Failsafe state = FS_2.
Clock register
Y
set is active,
X
is inactive.
Clock register
X
set is active,
Y
is inactive.
No GO_CLOCKS pending (default).
GO_CLOCKS pending, waiting for frame.
No CLEAR_FALLBACK pending (default).
CLEAR_FALLBACK pending, waiting for frame.
No FORCE_FALLBACK pending (default).
FORCE_FALLBACK pending, waiting for
frame.
6:4
FBSOP
111
000
001
010
011
100
101
0
1
0
1
0
1
0
1
3
XYSOB
2
GOPOB
1
CFPOB
0
FFPOB