User's Manual

35
Interface Signals
The Modem will communicate with the host through an interface with the following
signals:
Bus
Pin
Interface Function Signal
direction
µC*
µC Function
1 RTS
Or Data Out SPI (
1
)
O RTS ! Request To Send
Data Out SPI ! Data out during the programming of the Flash
Program.
2 Ack_Tx
Or Clock In SPI (
1
)
I/O Ack_Tx ! Transmission Ok
Clock In SPI ! Clock In during the programming of the Flash
Program.
3 N.U. - -
4 RXD I RxD UART - Serial Data Reception
5 CTS
Or Data In SPI (
1
)
I CTS ! Clear To Send
Data In SPI ! Data In during the programming of the Flash
Program.
6 TXD O TxD UART - Serial Data Transmission
7 VDD - 5 volts power for digital ("noisy").
8 LOCK O Network Synchronization Ok.
9 RESET I External Reset. Also used during the programming of the Flash
Program.
10 GND - Ground
11 N.U. I -
12 N.U. I -
13 N.U. I -
14 N.U. I -
((
1
): SPI hardware only in slave. The user is connected to this bus only in Flash/EEPROM
Programming: In this case, the RESET signal has to be on.
*I = Input O = Output
NOTE: The connector used is the 14FMS-1.0SP-TF 14-pin manufactured and distributed by
JST.