User's Manual

Table Of Contents
AT+i Command Set
AT+i Programmer‘s Manual Version 8.32 1-3
USART0
USART1
USART2
USB Device (identifies itself as a CDC device)
USB Host (supports only USB Modem class)
Available modem interfaces are:
USART0
USART1
USART2
USB Device
USB Host (only Motorola G24 USB GSM modem is supported)
As a USB host/device, iChip supports the Full-Speed USB standard (12Mbps).
Host-to-iChip interface is selected by setting the value of the Host Interface (HIF)
parameter. Any value from 1 to 5 specifies a certain choice of interface, while a 0 value
specifies automatic interface detection. In automatic interface detection mode, the first
character sent from the host over one of the supported interfaces sets the host interface to
be used throughout that session until the next iChip power cycle.
When automatic host interface detection mode is enabled, a host is connected to one of
the USARTs, and the Host Fixed Baud Rate (BDRF) parameter is set to ‗a‘ (automatic
baud rate detection), the first character the host has to send to iChip in order to trigger
detection must be an ‗a‘ or ‗A‘. If BDRF is set to a fixed baud rate, any character sent
from the host triggers automatic host interface detection.
In a similar fashion, an iChip-to-modem interface can be selected using the Modem
Interface (MIF) parameter, except that automatic modem interface detection is not
available.
Note that any changes to the HIF and MIF parameters take effect only after the following
iChip power-up. Also note that iChip cannot be operated in SerialNET mode when the
HIF parameter is set to automatic mode. Sending an SNMD command (activate
SerialNET mode) with HIF set to automatic mode will result in an error message
I/ERROR (122). In addition, any feature that requires setting a fixed baud rate requires
setting a fixed host interface, as well.
Hardware flow control is supported on USART0 and USART1 only. Hardware signal
mirroring is enabled only if the host and modem interfaces are set to either USART0 or
USART1. See description of Bit 2 of the FLW parameter.
1.7 Auto Baud Rate Detection
iChip supports auto baud rate detection on the host serial communications line. After
power-up, iChip enters auto baud mode when the
BDRF parameter is set to the value ‗a‘.
The AT+iBDRA command forces iChip into auto baud mode while it is already in
operation.