User's Manual

LISA-U1/LISA-H1 series - System Integration Manual

3G.G2-HW-10002-2 Advance Information System description

Page 56 of 116

Reference

Description

Part Number - Manufacturer

D1, D2, D3

Very Low Capacitance ESD Protection

PESD0402-140 - Tyco Electronics

100 nF Capacitor Ceramic X7R 0402 10% 16 V

GRM155R61A104KA01 - Murata

Table 21: Component for USB application circuit

If the USB interface is not connected to the application processor, it is highly recommended to provide

direct access to the VUSB_DET, USB_D+, USB_D- lines for execution of firmware upgrade over USB

and for debug purpose: testpoints can be added on the lines to accommodate the access. Otherwise, if

the USB interface is connected to the application processor, it is highly recommended to provide direct

access to the RxD, TxD, CTS and RTS lines for execution of firmware upgrade over UART and for debug

purpose. In both cases, provide as well access to RESET_N pin, or to the PWR_ON pin, or enable the

DC supply connected to the VCC pin to start the module firmware upgrade (see Firmware Update

Application Note [14]).

If the USB interface is not used, the USB_D+, USB_D- and VUSB_DET pins can be left unconnected,

but it is highly recommended to provide direct access to the lines for execution of firmware upgrade and

for debug purpose.

1.9.4 SPI interface

SPI is a master-slave protocol: the module runs as an SPI slave, i.e. it accepts AT commands on its SPI interface

without specific configuration. The SPI-compatible synchronous serial interface cannot be used for FW upgrade.

The standard 3-wire SPI interface includes two signals to transmit and receive data (SPI_MOSI and SPI_MISO)

and a clock signal (SPI_SCLK).

LISA-U1/LISA-H1 series modules provide two handshake signals (SPI_MRDY and SPI_SRDY), added to the

standard 3-wire SPI interface, implementing the 5-wire Inter Processor Communication (IPC) interface.

The purpose of the IPC interface is to achieve high speed communication (up to 20 Mb/s) between two

processors following the same IPC specifications: the module baseband processor and an external processor. The

high speed communication is possible only if both sides follow the same Inter Processor Communication (IPC)

specifications.

This interface is designated for high speed HSPA communications and could be necessary to communicate with

an Application Processor which is not equipped with a USB interface.