Board Revision Changes - XMOS XS1-L2 Hardware Manual

USB Audio 2.0 Reference Design, XS1-L2 Edition Hardware Manual (1.6) 31/32

19 Board Revision Changes

This sections lists the changes between revisions of the PCB.
19.1 Changes From 1V0 To 1V1
Swapped R62 and R66 silkscreen labels to correct error.
Removed GPIO test points and added GPIO connector
Split digital I/O to use seperate ports, rather than outputs being identical and the input
being selected by a switch.
Added testpoints for new digital I/O signals.
Added PLL AUX LED.
Added power sequencing to power supplies.
Moved R75, C75 and 13M oscillator to add power sequencing.
Changed layout of 1V0 SMPS.
Changed L2 footprint to improve solderability.
General tidy up and minor track changes.
19.2 Changes From 1V1 To 1V2
Added buffer for MIDI I/O to correct 5V going into XS1-L2 I/Os.
Added pull ups on MIDI signals to stop startup glitches.
Added 47pf cap to slow coax output and tidied up digital out layout.
Redesigned coaxial input for better performance and reduced cost.
Moved the optical input track away from the 1V0 SMPS inductor.
Moved bulk 1V0 decoupler (C93) across to far corner of L2.
Changed most 0402 decouplers to 0603.
Changed layout of the 13M oscillator.
Added 5 more ground test points (next to CLK, VBUS, MIDI, DIGITAL IN and DIGITAL
OUT).
Added silkscreen labels to all test points, apart from the codec signals in the middle of
the board.
Added silkscreen labels for 5V DC, POWER SW, USB, XSYS and GPIO.
Moved around R19, R52 and C34 to make it in line with other analogue outputs.
Tidied up teardrops and changed them to curved shape.
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