SNAS522K September 2011 – December 2023 LMK03806
PRODUCTION DATA
LMK03806 devices are programmed using 32-bit registers. Each register consists of a 5-bit address field and 27-bit data field. The address field is formed by bits 0 through 4 (LSBs) and the data field is formed by bits 5 through 31 (MSBs). The contents of each register is clocked in MSB first (bit 31), and the LSB (bit 0) last. During programming, the LEuWire signal should be held low. The serial data is clocked in on the rising edge of the CLKuWire signal. After the LSB (bit 0) is clocked in the LEuWire signal should be toggled low-to-high-to-low to latch the contents into the register selected in the address field. TI recommends to program registers in numeric order, for example R0 to R14, R16, R24, R26, and R28 to R31 to achieve proper device operation. Refer to the Timing Requirements for the timing for the programming.
To achieve proper frequency calibration, the OSCin port must be driven with a valid signal before programming register R30. Changes to PLL R divider or the OSCin port frequency require register R30 to be reloaded in order to activate the frequency calibration process.