5.1
Overview
SPRUFB3 – September 2007
Device Clocking
The DM355 requires one primary reference clock . The reference clock frequency may be generated
either by crystal input or by external oscillator. The reference clock is the clock at the pins named
MXI1/MXOI. The reference clock drives two separeate PLL controllers (PLLC1 and PLLC2). PLLC1
generates the clocks required by the ARM, VPBE, VPSS, and peripherals. PLL2 generates the clock
required by the DDR PHY. A block diagram of DM355's clocking architecture is shown in
. The
PLLs are described further in
Note:
Refer to the DM355 Data Manual (
SPRS348
) for information on supported device clocking
configurations (e.g. supported PLL configurations).
SPRUFB3 – September 2007
Device Clocking
35