Motorola MCF5282 Uart Mode Register 2 UMR2n, 3describes UMR2n fields, UMR2 n Field Descriptions

Models: MCF5282 MCF5281

1 816
Download 816 pages 28.97 Kb
Page 480
Image 480

Register Descriptions

23.3.2 UART Mode Register 2 (UMR2n)

The UMR2n registers control UART module configuration. UMR2n can be read or written when the mode register pointer points to it, which occurs after any access to UMR1n. UMR2n accesses do not update the pointer.

 

7

6

5

4

 

3

0

Field

 

CM

TxRTS

TxCTS

 

 

SB

 

 

 

 

 

 

 

 

Reset

 

 

 

0000_0000

 

 

 

 

 

 

 

 

 

R/W

 

 

 

R/W

 

 

 

 

Address

IPSBAR + 0x200 (UART0), 0x240 (UART1), 0x280 (UART2). After UMR1n is read or written, the pointer points to

 

 

 

 

UMR2n.

 

 

 

 

 

 

 

 

 

 

Figure 23-3. UART Mode Register 2 (UMR2n)

Table 23-3describes UMR2n fields.

 

 

 

 

 

 

 

 

 

Table 23-3. UMR2n Field Descriptions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

Name

 

 

 

 

 

 

 

 

 

 

 

 

Description

 

 

 

7–6

CM

Channel mode. Selects a channel mode. Section 23.5.3, “Looping Modes,” describes individual modes.

 

 

00

Normal

 

 

01

Automatic echo

 

 

 

10 Local loop-back

 

 

 

11 Remote loop-back

 

 

 

 

 

 

5

TxRTS

 

Transmitter ready-to-send. Controls negation of

 

to automatically terminate a message transmission.

RTS

 

 

 

Attempting to program a receiver and transmitter in the same channel for

RTS

control is not permitted and disables

 

 

 

RTS

control for both.

 

 

 

0 The transmitter has no effect on

RTS.

 

 

 

 

 

 

 

 

1 In applications where the transmitter is disabled after transmission completes, setting this bit automatically

 

 

 

 

 

clears UOP[RTS] one bit time after any characters in the channel transmitter shift and holding registers are

 

 

 

 

 

completely sent, including the programmed number of stop bits.

 

 

 

 

4

TxCTS

 

Transmitter clear-to-send. If both TxCTS and TxRTS are enabled, TxCTS controls the operation of the transmitter.

 

 

 

0

CTS

has no effect on the transmitter.

 

 

 

1 Enables clear-to-send operation. The transmitter checks the state of

CTS

each time it is ready to send a character.

 

 

 

 

 

If

CTS

is asserted, the character is sent; if it is negated, the channel TXD remains in the high state and

 

 

 

 

 

transmission is delayed until

CTS

is asserted. Changes in

CTS

as a character is being sent do not affect its

 

 

 

 

 

transmission.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

23-6

MCF5282 User’s Manual

MOTOROLA

Page 480
Image 480
Motorola MCF5282, MCF5281 user manual Uart Mode Register 2 UMR2n, 3describes UMR2n fields, UMR2 n Field Descriptions