Freescale Semiconductor M9328MX21ADSE Using The Board Connectors, Audio Indicator Buzzer

Configuration and Operation

2.3.11Audio Indicator (Buzzer)

The ADS includes an audio indicator or buzzer, U23. When S1-6 is ON, the PWMO pin of the i.MX21 controls this function. This buzzer operates from 1 KHz to 10 KHz. The maximum sound level is reached when the frequency is 3 KHz and the duty cycle is 50%.

2.3.12LED Indicators

Table 2-9shows the ADS LED indicators and their associated functions.

Table 2-9. Function of LED Indicators

Reference #	Color	Name	Function
LED1	Green	5V PWR	5 V power is ON
LED2	Green	VCC PWR	3 V power is ON
LED3	Orange	STAT 2	User status controlled by Output BIT 15*
LED4	Orange	STAT 1	User status controlled by Output BIT 14*
LED5	Green	ACTIVE	Blinking indicates LAN Activity
LED6	Orange	LINK	Link good or host controlled output
LED7	Red	BUS ACT	Blinking indicates external bus activity

*A logic high level at the controlling pin turns on the LED. A logic low turns it off.

2.4Using The Board Connectors

Table 2-10shows the ADS connectors and functions, as well as special instructions for using the connectors. Figure 1-1in Chapter 1 shows the connector locations and reference designators.

Table 2-10. M9328MX21ADSE Connectors

Connector	Function		Comments
P1	UART1	RS-232	DCE interface to UART1 of the i.MX21
P2	UART4	RS-232	DTE interface to UART4 of the i.MX21
P3	External UART	RS-232	DCE interface to Port A of the ST16C2552 UART
P4	USB OTG	USB On The Go mini AB connector
P5	Keypad module	Connect the Keypad ribbon cable between this connector and the
		corresponding connector of the Keypad Module, J1.
P6	SD/MMC	Slide the MMC card into the connector until it snaps into place.
P7	LCD panel	Connect LCD ribbon cable between this connector and the
		corresponding connector of the LCD display panel, J11.
P8	Power	Plug the 5-volt power-supply jack end into this connector.

	M9328MX21ADSE User’s Manual, Rev. A
2-12	Freescale Semiconductor