3 status register (pscsrn), Status register (pscsrn) -8, 3 status register (pscsr n ) – Freescale Semiconductor MCF5480 User Manual
Page 770
MCF548x Reference Manual, Rev. 3
26-8
Freescale Semiconductor
26.3.3.3
Status Register (PSCSRn)
The PSCSR register indicates the status of the characters in the FIFO and the status of the transmitter and
receiver.
4
TXCTS
Transmitter clear-to-send (UART and SIR modes). If both TxCTS and TxRTS are enabled, TxCTS
controls the operation of the transmitter.
0 PSCnCTS has no effect on the transmitter.
1 Enables clear-to-send operation. The transmitter checks the state of PSCnCTS each time it is ready
to send a character. If PSCnCTS is asserted, the character is sent; if it is negated, the channel
PSCnTXD remains in the high state and transmission is delayed until PSCnCTS is asserted.
Changes in PSCnCTS as a character is being sent do not affect its transmission.
3–0
SB
Stop-bit length control (UART mode only). Selects the length of the stop bit appended to the transmitted
character. Stop-bit lengths of 9/16th to 2 bits are programmable for 6–8 bit characters. Lengths of 1
1/16th to 2 bits are programmable for 5-bit characters. In all cases, the receiver checks only for a high
condition at the center of the first stop-bit position, that is, one bit time after the last data bit or after the
parity bit, if parity is enabled.
If an external 1x clock is used for the transmitter, clearing bit 3 selects one stop bit and setting bit 3
selects two stop bits for transmission.
An external clock source can be used to generate the baud rate. This is done by configuring the
communications timer. Please refer to the about external clock sources. Also refer to
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
RB_
NEOF
FE_
PHYERR
PE_
CRCERR
OE
TXEMP_
URERR
TX
RDY
FU
RX
RDY
CDE_
DEOF
ERR
0
0
0
0
0
0
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reg
Addr
MBAR + 0x8604 (PSC0); 0x8704 (PSC1); 0x8804(PSC2); 0x8904 (PSC3)
Figure 26-4. PSC Status Register (PSCSRn)
Table 26-4. PSCMR2n Field Descriptions
Bits
Name
Description
SB
5
Bits
6–8
Bits
SB
5 Bits
6–8
Bits
SB
5–8
Bits
SB
5–8
Bits
0000 1.063 0.563
0100 1.313 0.813
1000
1.563
1100 1.813
0001 1.125 0.625
0101 1.375 0.875
1001
1.625
1101 1.875
0010 1.188 0.688
0110 1.438 0.938
1010
1.688
1110 1.938
0011 1.250 0.750
0111 1.500 1.000
1011
1.750
1111 2.000