Register Descriptions

 

 

 

Table 23-5. UCSRn Field Descriptions

 

 

 

 

Bits

Name

 

Description

 

 

 

7–4

RCS

Receiver clock select. Selects the clock source for the receiver channel.

 

 

1101

Prescaled system clock

 

 

1110 DTIN divided by 16

 

 

1111

DTIN

 

 

 

3–0

TCS

Transmitter clock select. Selects the clock source for the transmitter channel.

 

 

1101

Prescaled system clock

 

 

1110 DTIN divided by 16

 

 

1111

DTIN

 

 

 

 

23.3.5 UART Command Registers (UCRn)

The UCRs, shown in Figure 23-6,supply commands to the UART. Only multiple commands that do not conflict can be specified in a single write to a UCRn. For example,

RESET TRANSMITTER and ENABLE TRANSMITTER cannot be specified in one command.

Field

Reset

R/W Address

7

6

4

3

2

1

0

MISC

 

 

TC

 

RC

 

 

 

 

 

 

 

0000_0000

Write only

IPSBAR + 0x208(UCR0), 0x248(UCR1), 0x288(UCR2)

Figure 23-6. UART Command Register (UCRn)

Table 23-6describes UCRn fields and commands. Examples in Section 23.5.2, “Transmitter and Receiver Operating Modes,” show how these commands are used.

MOTOROLA

Chapter 23. UART Modules

23-9

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Motorola MCF5281, MCF5282 user manual Uart Command Registers UCRn, UCSRn Field Descriptions, Rcs, Dtin, Misc