Texas Instruments MSC1211 - Manual (Page 20)

Switches
3-4
3.2 Switches
3.2.1 RESET Switch
Switch SW1 is a miniature pushbutton that, when pressed, forces the
MSC1211 RST line high. When released, the MSC1211 enters a reset cycle.
If communication becomes disrupted between the host and the board, or the
board is unresponsive, pressing RESET will return the system to normal op-
eration.
3.2.2 INT Switch
Switch SW2 is a miniature pushbutton that, when pressed, shorts Port 3.2 to
ground. This pin is the INT0 pin and, therefore, can be setup to cause an inter-
rupt when this pin goes low.
3.2.3 SW3: Configuration Switch
SW3 provides the means to enable or disable many of the function on the
MSC1211EVM.
Table 3–2. SW3: Configuration Control Switch
Switch
Number Function
1 Enables pin P3.5 to control the Yellow LED D5
2 Enables pin P3.4 to control the Red LED D4.
3 Enables pin P3.3 to drive the speaker.
4 Enables pin P3.0 to receive data from Serial0 (J5)
5 Disables on–board 22.1184MHz crystal oscillator
6 Enables pin P1.2 to receive data from Serial1 (J4)
7 Allows DTR from Serial0 to reset MSC1211
8 Allows RTS from Serial0 to reset to Prog Load mode
3.2.4 PRG LD Switch
SW4 is a miniature pushbutton that, when pressed, forces the MSC1211 RST
line high. It also pulls the PSEN line low so that when released, the MCU will
enter a reset cycle in the Program Load mode. Program execution will be from
the on-chip ROM, and it starts by waiting for a carriage return so that it can per-
form an autobaud function.