Sony Ericsson GM48, GM47 manual Rd, Td Rts, Cts, Dtr, Dcd, Ri, Off

GM47/GM48 INTEGRATOR’S MANUAL

Note! UART1 signal levels do not match standard RS232 (V.28) levels. The relationship between the levels is shown in the table below.

RS232 level	RD, TD	RTS, CTS, DTR, DCD, RI	CMOS level
<– 3V	1	OFF	>1.93V
>+3V	0	ON	<0.80V

Conversion between the module CMOS levels and RS232 levels can be achieved using a standard interface IC, such as the Maxim Integrated Products MAX3237.

2.8.2 Serial Data Signals - RD, TD

The default baud rate is 9.6kbits/s, however higher bit rates of up to 460 kbits/s are supported, set by an AT command. UART1 starts at a rate of 9.6kbits/s in standard AT command mode. The module also supports GSM 07.10 multiplexing protocol and starts when the appropriate command is sent.

Serial Data From Module (RD)

RD is an output signal that the module uses to send data via UART1 to the application.

Parameter	Limit
Application load resistance	≥100kΩ
Application load capacitance	<100pF

Serial Data To Module (TD)

TD is an input signal, used by the application to send data via UART1 to the module.

Parameter	Limit
Application driving impedance	<100Ω
Input capacitance	<100pF
Input resistance	<100Ω in series, with 100kΩ to DGND

2.8.3 Control Signals - RTS, CTS, DTR, DCD, RI

UART1 control signals are active low and need a standard interface IC, such as the MAX3237, to generate standard RS232 levels.

UART1 converted signals, together with DGND, RD and TD form a 9-pin RS232 data port.

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