SCSI2SD Schematic Notes: Difference between revisions
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m Created page with "Details for the circuit design of [SCSI2SD]. == Crystal Oscillator == * LCP1751 requires a 25MHz crystal, which results in a 100MHz clock with x4 PLL * The crystal requires 2 ca…" |
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Details for the circuit design of [SCSI2SD]. | Details for the circuit design of [[SCSI2SD]]. | ||
== Crystal Oscillator == | == Crystal Oscillator == | ||
Revision as of 03:53, 7 October 2011
Details for the circuit design of SCSI2SD.
Crystal Oscillator
- LCP1751 requires a 25MHz crystal, which results in a 100MHz clock with x4 PLL
- The crystal requires 2 caps for stability. The required value is:
2 * (CL - CS)
Where CL is the crystal's load capacitance, as specified by the crystal manufacturer, and CS is the PCB's stray capacitance (around 5pF for a reasonable PCB).
3.3V Regulator
LM1117-3.3 Notes on cap values Notes on required current Notes on switching frequency
In-circuit programming
UART0 pins, + active low program enable power supply while programming ? Custom header ? Custom bootloader as well ?
Switches
TERMPWR, terminator, parity, SCSI ID
