Specifications

Confidential

Page 12

 The configurable RAM/ROM connector for the internal storage controller and external Flash

can be connected

 Connect the data RAM connector of the storage controller

 Access the AHB port of the register

4.2 storage

The LF-WM03 chip has a built-in storage controller that includes ROM and SRAM. With

276KB SRAM,128KB ROM, and 1Kb eFuse. 2MB Flashis integrated inside thechip.

4.3 Crystal

The LF-WM03 enables the use of 40MHz crystals, which are selected with an

accuracy of ±10 PPM , and load capacitor of less than 12pF.

Note:

 The accuracy of the selected crystal itself needs to be10ppm±, and the operating temperature of

the crystal is -20 °C to 85 °C;

 The location of the crystal oscillator should be as close as possible to the XTAL Pins of the

chip (the traces should not be too long), and the traces of the crystal oscillator must be

grounded and shielded.

 The input and output lines of the crystal cannot be punched into the line, i.e. they cannot cross

layers. The input and output lines of the crystal cannot cross, nor can the cross-layer cross-overs.

 The capacitance of the switch of the input and output of the crystal should be placed near the

left and right side of the chip and should not be on the line as far as possible.

 Crystals Below can not go up frequency digital signal, the best case is the crystal below do not

take any signal lines, crystal TOP surface of the copper-paved area the bigger the better.

Crystals are sensitive devices, and there can be no magnetic induction devices around the

crystal, such as large inductors.