Motorola MCF5282 Uart Baud Rate Generator Registers UBG1n/UBG2n, Uisr n/UIMR n Field Descriptions

Models: MCF5282 MCF5281

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Register Descriptions

Table 23-9describes UISRn and UIMRn fields.

 

 

 

Table 23-9. UISRn/UIMRn Field Descriptions

 

 

 

 

 

 

Bits

Name

 

 

 

Description

 

 

 

7

COS

Change-of-state.

 

 

0

UIPCRn[COS] is not selected.

 

 

1

Change-of-state occurred on

CTS

and was programmed in UACRn[IEC] to cause an interrupt.

 

 

 

6–3

Reserved, should be cleared.

 

 

 

2

DB

Delta break.

 

 

0

No new break-change condition to report. Section 23.3.5, “UART Command Registers (UCRn),”

 

 

 

describes the RESET BREAK-CHANGE INTERRUPT command.

 

 

1

The receiver detected the beginning or end of a received break.

 

 

 

1

FFULL/

RxRDY (receiver ready) if UMR1n[FFULL/RxRDY] = 0; FIFO full (FFULL) if

 

RxRDY

UMR1n[FFULL/RxRDY] = 1. Duplicate of USRn[FFULL/RxRDY]. If FFULL is enabled for UART0

 

 

or UART1, DMA channels 2 or 3 are respectively interrupted when the FIFO is full.

 

 

 

0

TxRDY

Transmitter ready. This bit is the duplication of USRn[TxRDY].

 

 

0

The transmitter holding register was loaded by the CPU or the transmitter is disabled. Characters

 

 

 

loaded into the transmitter holding register when TxRDY = 0 are not sent.

 

 

1

The transmitter holding register is empty and ready to be loaded with a character.

 

 

 

 

 

 

23.3.11 UART Baud Rate Generator Registers (UBG1n/UBG2n)

The UBG1n registers hold the MSB, and the UBG2n registers hold the LSB of the preload value. UBG1n and UBG2n concatenate to provide a divider to the system clock for transmitter/receiver operation, as described in Section 23.5.1.2.1, “System Clock Baud Rates.”

Field

Reset

R/W Address

Field

Reset

R/W Address

7

0

Divider MSB

0000_0000

W

IPSBAR + 0x218 (UBG10), 0x258 (UBG11), 0x298 (UBG12)

Figure 23-12. UART Baud Rate Generator Register (UBG1n)

7

0

Divider LSB

0000_0000

W

IPSBAR + 0x21C (UBG20), 0x25C (UBG21) 0x29C (UBG22)

Figure 23-13. UART Baud Rate Generator Register (UBG2n)

23-14

MCF5282 User’s Manual

MOTOROLA

Page 488
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Motorola MCF5282, MCF5281 user manual Uart Baud Rate Generator Registers UBG1n/UBG2n, 9describes UISRn and UIMRn fields