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PRELIMINARY
UART
S3C6400 RISC MICROPROCESSOR
31-22
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
UART MODEM STATUS REGISTER
There are two UART modem status registers including UMSTAT0 and UMSTAT1 in the UART block.
nCTS
Delta CTS
Read_UMSTAT
Figure 31-8
nCTS and Delta CTS Timing Diagram
Register
Address
R/W
Description
Reset Value
UMSTAT0
0x7F00501C
R
UART channel 0 Modem status register
0x0
UMSTAT1
0x7F00541C
R
UART channel 1 Modem status register
0x0
Reserved 0x7F00581C
-
Reserved
Undef
Reserved 0x7F005C1C
-
Reserved
Undef
UMSTAT0
Bit
Description
Initial State
Reserved [7:5]
reserved
000
Delta CTS
[4]
Indicate that the nCTS input to the S3C6400 has changed
state since the last time it was read by CPU. (Figure 31-8)
0 = Has not changed
1 = Has changed
0
Reserved [3:1]
reserved
00
Clear to Send
[0]
0 = CTS signal is not activated (nCTS pin is high)
1 = CTS signal is activated (nCTS pin is low)
0