Artesyn MVME2502, Инструкция по установке и эксплуатации, Страница: 151 / 164

Programming Model
MVME2502 Installation and Use (6806800R96D)
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7.7 Clock Distribution
The clock function generates and distributes all the clocks required for system operation. The
ICS9FG108 is used to generate all the required PCI-E clocks. The 25 MHz clocks for the Ethernet
PHY and SATA bridge are supplied by ICS83905 device. Most of the QorIQ P2020 clocks are
generated by ICS840S07I device. Additional clocks required by individual devices are
generated near the devices using individual oscillators. The following table lists the clocks
required on the MVME2502 along with the frequency and source.
SETA External address termination
0 - Access is terminated internally by the memory controller unless the
external device asserts LGTA earlier to terminate the access.
TRLX Timing Relaxed
0 - Normal timing is generated by the GPCM.
EHTR Extended hold time on read accesses.
0 - The memory controller generates normal timing. No additional cycles
are inserted
EAD External address latch delay
0 - No additional bus clock cycles (LALE asserted for one bus clock cycle
only)
Table 7-6 Clock Distribution
Device Clock Signal Frequency Clock Tree Source VIO
QorIQ P2020 CPU_SYSCLK 100MHz ICS840S07I +3.3V
QorIQ P2020 CPU_DDR_CLK 100MHz ICS840S07I +3.3V
QorIQ P2020 CLK_PCI_BR3 133Mhz ICS840S07I +3.3V
QorIQ P2020 EC_GTX_CLK125 125Mhz ICS840S07I +3.3V
ICS840S07I CLK_25MHZ_ICS840S07 25Mhz ICS83905AGILF +3.3V
88SE9125 CLK_88SE9125_25MHZ 25Mhz ICS83905AGILF +3.3V
ICS9FG108 CLK_25MHZ_ICS9FG108 25Mhz ICS83905AGILF +3.3V
BCM54616S BP_PHY_25MHZ_CLK 25Mhz ICS83905AGILF +3.3V
BCM54616S FP_PHY_25MHZ_CLK 25Mhz ICS83905AGILF +3.3V