Freescale Semiconductor M9328MX21ADSE UART4 Connector, Connector P2 UART4 DTE Signal Descriptions

Support Information

3.4.2UART4 Connector

Connector P2 connects to the UART4 pins of the i.MX21 MCU. UART4 is the secondary functionality of these pins. This male DB9 connector is configured for RS-232 DTE operation. Figure 3-6shows pin assignments and Table 3-6provides signal descriptions for the connector.

C

D

R

X

D

T

X

D

D

T

R

G

N

D

1

2

3

4

5

P2

6

7

8

9

S

R

T

S

T

S

I

D

R

C

R

Figure 3-6. Connector P2 (UART4) DTE Pin Assignments

Table 3-6. Connector P2 (UART4) DTE Signal Descriptions

Pin

Signal

Description

1

CD

CARRIER DETECT — RS-232 input signal, can be jumpered to SD2_D2 at J5 or ignored

2

RXD

RECEIVED DATA — RS-232 serial data input signal, connected to USBH1_TXDP when

UART4 is enable.

3

TXD

TRANSMITTED DATA — RS-232 serial data output signal, connected to USBH1_TXDM

when UART4 is enabled

4

DTR

DATA TERMINAL READY — RS-232 output signal, can be jumpered to SD2_D0 or forced

active positive at J3

5

GND

GROUND

6

DSR

DATA SET READY — RS-232 input signal, can be jumpered to SD2_D1 at J4 or ignored,

active positive

READY TO SEND — RS-232 output signal, active positive, connected to USBH1_RXDM

7

RTS

when UART4 is enabled

CLEAR TO SEND — RS-232 input signal, active positive, connected to USBH1_RXDP

8

CTS

when UART4 is enabled

9

RI

RING INDICATOR — RS-232 input signal, active positive, can be jumpered to SD2_D3 at

J6 or ignored

	M9328MX21ADSE User’s Manual, Rev. A
Freescale Semiconductor	3-19