One Stop Systems, Inc. OSS-wanPCI-CxT1E1 User Manual
Rev. A
13
Master Clock Registers (MCSR)
Note:
The backplane clock is the clock between the COMET and the MUSYCC.
The COMET decides if the backplane clock is sourced by the central office or the onboard oscillator
Master Clock register and Board Type Register
The framers require a MCLK that can be either T1 (1.544MHz) or E1 (2.048MHz). Two onboard oscillators are provided to be the
source of those clocks. The MCLK register is used to select between the two oscillators. The MCLK register is a write/read register
set to default to zero after powerup or system reset.
The MCLK Register is a read/write register combined with the Board
Type Register (BTYP), a read-only register. The power-up default value of this combined register is X0 Hex, where X
depends on the number of ports available on the board. Each COMET requires an MCLK that can be either T1 (1.544
MHz) or E1 (2.048 MHz). Two on-board oscillators are provided to be the source of those clocks. The MCLK Register is
used to select between the two oscillators for each port.
BTYP Register – Address = 0xD0001
MCLK Register – Address = 0xD0001
Read Only
Read/Write
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reserved
Reserved
Type 1
Type 0 Port 3
Port 3
Port 1
Port 0
Port0 = 0 COMET 0 MCLK = T1
Port 0= 1 COMET 0 MCLK = E1
Port1 = 0 COMET 1 MCLK = T1
Port 1= 1 COMET 1 MCLK = E1
Port2 = 0 COMET 2 MCLK = T1
Port2= 1 COMET 2 MCLK = E1
Port3 = 0 COMET 3 MCLK = T1
Port 3= 1 COMET 3 MCLK = E1
Type[1:0] = 00 4 Ports Available
= 01 1 Ports Available
= 10 2 Ports Available
Other values are reserved for future products. Bits 7 and 8 are Reserved bits
MCSR Clock
Source
00 Hex
All ports (COMETs) use their individual backplane clock as the clocksource used by their respective MUSYCC ports.
NOTE: All COMETs must be initialized in master mode.
COMET 1 provides clocking to MUSYCC port 0.
COMET 2 provides clocking to MUSYCC port 1.
COMET 3 provides clocking to MUSYCC port 2.
COMET 4 provides clocking to MUSYCC port 3.
01 Hex
Port 1 (COMET 1) uses its backplane clock to provide the source clocking for all other COMETs including the
MUSYCC ports. NOTE: COMET 1 must be initialized in master mode. COMETs 2, 3, and 4 must be initialized in
slave mode.
02 Hex
Port 2 (COMET 2) uses its backplane clock to provide the source clocking for all other COMETs including the
MUSYCC ports. NOTE: COMET 2 must be initialized in master mode. COMETs 1, 3, and 4 must be initialized in
slave mode.
03 Hex
Port 3 (COMET 3) uses its backplane clock to provide the source clocking for all other COMETs including the
MUSYCC ports. NOTE: COMET 3 must be initialized in master mode. COMETs 1, 2, and 4 must be initialized in
slave mode.
04 Hex
Port 4 (COMET 4) uses its backplane clock to provide the source clocking for all other COMETs including the
MUSYCC ports. NOTE: COMET 4 must be initialized in master mode. COMETs 1, 2, and 3 must be initialized in
slave mode.
