OPB 16450 UART

4

DS433 August 18, 2004

1-800-255-7778

Product Specification

Parameter - Port Dependencies

The width of many of the OPB UART signals depends on parameter. In addition, when certain features are parameterized

away, the related input signals are unconnected. The dependencies between the OPB UART design parameters and I/O sig-

nals are shown in Table 3. parameters and I/O signals are shown in the following table.

UART

Signals

P13

baudoutN

Serial

O

1

Transmitter Clock

P14

rclk

Serial

I

Receiver 16x Clock (Optional.

May be driven by baudoutN

under control of the

C_HAS_EXTERNAL_RCLK

parameter).

P15

sin

Serial

I

Serial Data Input

P16

sout

Serial

O

1

Serial Data Output

P17

xin

Serial

I

Baud Rate Generator reference

clock. (Optional. May be driven

by OPB_Clk under control of the

C_HAS_EXTERNAL_XIN

parameter).

P18

xout

Serial

O

~XIN

Inverted XIN

P19

ctsN

Modem

I

ClearToSend (active low)

P20

dcdN

Modem

I

Data Carrier Detect (active low)

P21

dsrN

Modem

I

Data Set Ready (active low)

P22

dtrN

Modem

O

1

Data Terminal Ready (active

low)

P23

riN

Modem

I

Ring Indicator (active low)

P24

rtsN

Modem

O

1

Request To Send (active low)

P25

ddis

User

O

1

Driver Disable. Low when CPU

is reading OPB UART

P26

out1N

User

O

1

User controlled output

P27

out2N

User

O

1

User controlled output

P28

rxrdyN

User

O

1

DMA control signal

P29

txrdyN

User

O

1

DMA control signal

System

P30

OPB_Clk

System

I

System clock

P31

OPB_Rst

System

I

System Reset (active high)

P32

Freeze

System

I

Freezes UART for software

debug (active high)

Table 2: UART I/O Signals (Continued)

Grouping

Signal Name

Interface

I/O

Initial

diagra

m State

Description