Freescale Semiconductor M9328MX21ADSE User Manual

2-12

Freescale Semiconductor

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%.

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

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

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.

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.