Released
Datasheet
PM73487 QRT
PMC-Sierra, Inc.
PMC-980618
Issue 3
622 Mbps ATM Traffic Management Device
11.3 Connecting the QRT to the S/UNI-ATLAS PM7324
The S/UNI-ATLAS PM7324 is a full duplex Fault Management (FM) OAM, Performance Man-
agement (PM) OAM, and policing device. It has a UTOPIA interface on the PHY side and a SAT-
URN interface on the other side. It can interface directly to the QRT by utilizing the QRT’s OC-
12 single phy mode. In the UTOPIA_CONFIG register (refer to “7.2.11 UTOPIA_CONFIG”
starting on page 117), RX_OC_12C_MODE should be set to 1, TX_OC_12C_MODE can be set
to either 0 or 1, and UTOPIA_2 should be set to 1. Please refer to the PMC document PM980583
for a detailed description of this application
Figure 73 shows an example of connecting the QRT to the S/UNI-ATLAS.
Receive Cell
SSRAM
SDRAM
RX_OC_12C_MODE = 1
Receive UTOPIA Level 2
ATLAS
To QSE
QRT
(PM73487)
Transmit UTOPIA Level 2
PM7324
Host Interface
From QSE
TX_OC_12C_MODE = 1
UTOPIA_2 = 1
Transmit Cell
SDRAM
Control
SSRAM
Figure 73. Connecting the QRT to the RCMP-800
11.4 Relationships Among Various Clock Domains
Relationships among various clock domains on the QRT are complex and require careful consid-
eration for effective use of the device and optimal performance. Duty cycle tolerance for
SYSCLK, ATMCLK, SE_CLK and PCLK is 60/40.
.
The maximum operating frequency of the QRT is 100 MHz; however, it is possible to operate the
QRT at frequencies below 100 MHz if various relationship constraints are met. Frequency rela-
tionships also determine the switch speed-up factor and device throughput. Phase aligners only
converge in a certain frequency range. DRAMs may potentially lose data below a certain operat-
ing frequency, and during processor transactions data integrity is guaranteed if the ATM_CLK-to-
SYSCLK relationship is maintained.
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PMC [ PMC-SIERRA, INC ]
