Information

DUART
MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1
18-14 Freescale Semiconductor
18.3.1.10 Scratch Registers (USCR1 and USCR2)
USCR, shown in Figure 18-12, are for debugging software or the DUART hardware. The USCRs do not
affect the operation of the DUART.
Table 18-17 describes USCR fields.
18.3.1.11 Alternate Function Registers (UAFR1 and UAFR2)
The UAFRs, shown in Figure 18-13, allow software to write to both UART1 and UART2 registers
simultaneously with the same write operation. The UAFRs also provide a means for the device's
performance monitor to track the baud clock.
6 OE Overrun error
0 Cleared when ULSR is read
1 Before URBR was read, it was overwritten with a new character. The old character is lost. In FIFO mode,
the receiver FIFO is full (regardless of the receiver FIFO trigger level setting) and a new character has been
received into the internal receiver shift register. The old character was overwritten by the new character.
Data in the receiver FIFO was not overwritten.
7 DR Data ready
0 Cleared when URBR is read or when all of the data in the receiver FIFO is read.
1 A character was received in the URBR or the receiver FIFO.
Offset: 0x0_4507, 0x0_4607 Access: User read/write
0 7
R
DATA
W
Reset All zeros
Figure 18-12. Scratch Register (USCR)
Table 18-17. USCR Field Descriptions
Bits Name Description
0–7 DATA Data
Offset: 0x0_4502, 0x0_4602 Access: User read/write
0 567
R
—BOCW
W
Reset All zeros
Figure 18-13. Alternate Function Register (UAFR)
Table 18-16. ULSR Field Descriptions (continued)
Bits Name Description