ST16C580
hardware flow control. -RTS functions normally when
hardware flow control is disabled.
SIGNALS
RESETSTATE
TX
Logic 1
Logic 1
Logic 1
Logic 1
Logic 1
Logic 1
Logic 0
Logic 0
0 = Automatic RTS flow control is disabled. (normal
default condition)
1 = Enable Automatic RTS flow control.
-OP1
-OP2
-RTS
-DTR
-RXRDY
-TXRDY
INT
EFR bit-7:
Automatic CTS Flow Control.
Logic 0 = Automatic CTS flow control is disabled.
(normal default condition)
Logic 1 = Enable Automatic CTS flow control. Trans-
mission will stop when -CTS goes to a logical 1.
Transmission will resume when the -CTS pin returns
to a logical 0.
ST16C580 EXTERNAL RESET CONDITIONS
REGISTERS
RESET STATE
IER
ISR
IER BITS 0-7 = logic 0
ISR BIT-0=1, ISR BITS 1-7 = logic
0
LCR, MCR
LSR
BITS 0-7 = logic 0
LSR BITS 0-4 = logic 0,
LSR BITS 5-6 = logic 1 LSR, BIT
7 = logic 0
MSR
MSR BITS 0-3 = logic 0,
MSR BITS 4-7 = logic levels of the
input signals
FCR, EFR
BITS 0-7 = logic 0
Rev.1.20
26
EXAR [ EXAR CORPORATION ]
