User Manual

Redpine Signals, Inc. Page 47
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RS9110-N-11-24
Evaluation Board User Guide
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Signal Integrity Guidelines for SPI interface: Glitches in the SPI clock can
potentially take the SPI interface out of synchronization. The quality and integrity of
the clock line needs to be maintained. The following steps are recommended.
Please note that this is not an exhaustive list of guidelines and depending on
individual cases additional steps may be needed.
1. It is recommended to avoid using cables to connect the Host platform with the
module’s SPI interface. In case a cable is used, minimize the length of the SPI bus
cable to as small as possible, preferably to within an inch or two
2. It is recommended to use a companion card with a rigid connector to the host
3. If a cable is used, increase the number of ground connections between the WiFi
PCB and the MCU PCB
4.1 TCP/IP Stack Usage in RS9110-N-11-24–SPI mode
RS9110-N-11-22, RS9110-N-11-24 and RS9110-N-11-28 are Wi-Fi
modules with integrated TCP/IP stack. This reduces the development
effort for designers who don’t want to integrate a TCP/IP stack in their
Host platform. However, there are applications where the designer wants
to run his own TCP/IP stack on the Host. The TCP/IP stack in the
mentioned modules can be bypassed in such scenarios. This feature of
bypassing the stack is available from firmware version 4.5.0 onwards.
4.1.1 Using the Wi-Fi module with TCP/IP stack enabled
The Wi-Fi module is by default in “TCP/IP stack enabled” mode.
1. The reference driver that the user should use for this mode is placed
inside RS.CN.xx.GENR.SP.x.x.x/Driver/Driver_TCP
2. The API manual that should be used is placed in
RS.CN.xx.GENR.SP.x.x.x/Driver/Driver_TCP/Documentation/