Specifications

L506 Hardware Design

3.12.3 SD card signal PCB line rules

Due to the SD signal is the high-speed digital interface, so it’s layout rules should be in accordance

with the high speed digital rules.

1.Protect other sensitive signals/circuits from SDC corruption.

2. Protect SDC signals from noisy signals (clocks, SMPS, etc.).

3. 50 Ω nominal, ±10% trace impedance.

4. CLK to DATA/CMD length matching < 1 mm.

5. Total routing length < 50 mm recommended.

6. Spacing to all other signals = 2x line width.6 Bus capacitance < 15 pF.

3.13 System boot configuration and download

3.13.1 Pin definition

L506 can configure BOOT_CONFIG (Boot Configuration) pin to Configuration module power-on

mode and the forced entry USB download mode.

Table 3-23 Boot configurationand force USB download

Pin No.

Net name

Function description

note

BOOT_CFG0

Pull up this pin change boot

configurationregister value

BOOT_CFG1

Pull up this pin change boot

configurationregister value

COEX2(Syste

m on)

FOCE_USB_BOOT(

before system

on)

Pull up this pin change boot

configurationregister value

Multiplex

3.13.2 Boot configuration and force USB interface application