AR-B1579 User
’
s Guide
2-8
(5) Line Control Register (LCR)
Bit 0: Word Length Select Bit 0 (WLS0)
Bit 1: Word Length Select Bit 1 (WLS1)
WLS1 WLS0
Word
Length
0 0
5
Bits
0 1
6
Bits
1 0
7
Bits
1 1
8
Bits
Bit 2: Number of Stop Bit (STB)
Bit 3: Parity Enable (PEN)
Bit 4: Even Parity Select (EPS)
Bit 5: Stick Parity
Bit 6: Set Break
Bit 7: Divisor Latch Access Bit (DLAB)
(6) MODEM Control Register (MCR)
Bit 0: Data Terminal Ready (DTR)
Bit 1: Request to Send (RTS)
Bit 2: Out 1 (OUT 1)
Bit 3: Out 2 (OUT 2)
Bit 4: Loop
Bit 5: Must be 0
Bit 6: Must be 0
Bit 7: Must be 0
(7) Line Status Register (LSR)
Bit 0: Data Ready (DR)
Bit 1: Overrun Error (OR)
Bit 2: Parity Error (PE)
Bit 3: Framing Error (FE)
Bit 4: Break Interrupt (BI)
Bit 5: Transmitter Holding Register Empty (THRE)
Bit 6: Transmitter Shift Register Empty (TSRE)
Bit 7: Must be 0
(8) MODEM Status Register (MSR)
Bit 0: Delta Clear to Send (DCTS)
Bit 1: Delta Data Set Ready (DDSR)
Bit 2: Training Edge Ring Indicator (TERI)
Bit 3: Delta Receive Line Signal Detect (DSLSD)
Bit 4: Clear to Send (CTS)
Bit 5: Data Set Ready (DSR)
Bit 6: Ring Indicator (RI)
Bit 7: Received Line Signal Detect (RSLD)
