Service Guide
Table Of Contents
- Safety Information
- About the Document
- Contents
- Table Index
- Figure Index
- 1 Introduction
- 2 Product Overview
- 3 Operating Characteristics
- 4 Application Interfaces
- 5 Antenna Interfaces
- 6 Reliability, Radio, and Electrical Characteristics
- 7 Mechanical Information
- 8 Storage, Manufacturing, and Packaging
- 9 Appendix References
LTE Standard Module Series
EG915U_Series_Hardware_Design 52 / 90
4.8. SPI Interface
The module provides an SPI interface that only supports master mode. It has a working voltage of 1.8 V
and a maximum clock frequency of 25 MHz.
Table 22: Pin Definition of SPI Interface
4.9. PSM Interface*
The module supports power saving mode (PSM). It enters the PSM through the following AT commands
when working normally.
⚫ AT+CFUN=4: Enter airplane mode.
⚫ AT+QSCLK=3: Enable PSM.
⚫ AT+CFUN=1: Exit airplane mode.
Pulling up the PSM_EINT pin externally or setting the timer by software will enable the module to exit
PSM.
Pin Name
Pin No.
I/O
Description
Comment
SPI_CLK
26
DO
SPI clock
1.8 V power domain.
If unused, keep them
open.
SPI_CS
25
DO
SPI chip select
SPI_DIN
88
DI
SPI master mode input
SPI_DOUT
64
DO
SPI master mode output
When the 4-wire SPI interface is connected to NOR Flash, it supports basic flash read, write, erase, and
other operations, but you need to perform wear leveling. It does not support file system and can only be
used for storage purpose.
NOTE