Shared Commands

• Glitch (0xFF = Increment; 0xFE = Read)
• ID (0xFD = Reset; 0xFC = Read)
• Clock adjust (0xFB = Pulse, 0xFA = Read)
• Clock adjust (0xF9 = Incr, 0xF8 = Decr.)
• 4/6-bits of clock adjust ('509/'509A)