Datasheet

3.0 AC Electrical Characteristics T
A
e
0
§
Cto
a
70
§
C, V
DD
ea
5V
g
10% (Continued)
Symbol Parameter Conditions Min Max Units
TRANSMITTER
t
HR
Delay from WR (WR THR)
40 ns
to Reset Interrupt
t
IR
Delay from RD (RD IIR) to Reset
40 ns
Interrupt (THRE)
t
IRS
Delay from Initial INTR Reset
824
BAUDOUT
to Transmit Start Cycles
t
SI
Delay from Initial Write to Interrupt (Note 1)
16 24
BAUDOUT
Cycles
t
STI
Delay from Start to Interrupt (THRE) (Note 1)
8
BAUDOUT
Cycles
t
SXA
Delay from Start to TXRDY Active
8
BAUDOUT
Cycles
t
WXI
Delay from Write to TXRDY Inactive 25 ns
MODEM CONTROL
t
MDO
Delay from WR (WR MCR)
40 ns
to Output
t
RIM
Delay to Reset Interrupt from
78 ns
RD
(RD MSR)
t
SIM
Delay to Set Interrupt from MODEM Input 40 ns
Note 1: This delay will be lengthened by 1 character time, minus the last stop bit time if the transmitter interrupt delay circuit is active. (See FIFO Interrupt Mode
Operation).
4.0 Timing Waveforms All timings are referenced to valid 0 and valid 1
External Clock Input (24 MHz Max)
TL/C/9426–2
AC Test Points
TL/C/9426–3
Note 2: The 2.4V and 0.4V levels are the voltages that the inputs are driven to during AC testing.
Note 3: The 2.0V and 0.8V levels are the voltages at which the timing tests are made.
BAUDOUT Timing
TL/C/9426–4
5