AN3123

UART signals

Doc ID 16862 Rev 2

5/30

2

UART signals

SPEAr600 has 2 UARTs. SPEAr300, SPEAr310 and SPEAr320 have 1, 6 and 3 UARTs

respectively. The following tables list the UART pin connections and register base addresses

for each case.

2.1

SPEAr600

2.2

SPEAr300

Table 1.

External pin connection on SPEAr600

Signal name

Ball

Direction

Function

Pin type

UART1_TXD

AA19

Output

Serial Data Out

TTL output buffer

3.3 V capable, 4 mA

UART2_TXD

AA20

Output

UART1_RXD

AB19

Input

Serial Data In

TTL input buffer

3.3 V tolerant, PD

UART2_RXD

AB20

Input

Table 2.

Memory map on SPEAr600

Peripheral

Start address

End address

UART1

0xD000.0000

0xD007.FFFF

UART2

0xD008.0000

0xD00F.FFFF

Table 3.

External pin connection

Signal

Ball

Direction

Function

Pin type

RX DATA

D1

Input

Shared I/O

TTL output buffer

3.3 V capable,

up to 10 mA

TTL input buffer

3.3 V tolerant, PU/PD

TX DATA

E4

Output

RTS

B8

I/O

CTS

A8

DTR

D9

DSR

B9

DCD

A9

RI

C9

Table 4.

Memory map on SPEAr300

Peripheral

Start address

End address

UART

0xD000.0000

0xD007.FFFF