NS486SXF Datasheet, PDF (39/44 Pages) National Semiconductor (TI) – NS486TMSXF Optimized 32-Bit 486-Class Controller with On-Chip Peripherals for Embedded Systems

3 0 Device Specifications (Continued)
Symbol
Parameter
Min
Max
Units
t_SINT
t_STI
t_SI
t_IRS
t_MDO
t_RIM
t_SIM
Delay from Stop Bit to Set Interrupt
Delay from Start Bit to IRQ
Delay from Initial Write to IRQ
16
Delay from IRQ Reset to Tx Start
8
Delay from Write to Output
Delay to Reset IRQA from Read
Delay to Set IRQ from Modem Input
2
BAUDOUT Cycles
8
BAUDOUT Cycles
24
BAUDOUT Cycles
24
BAUDOUT Cycles
40
ns
78
ns
40
ns
Input Clock Frequency
BAUDOUT Cycle e
16 x Baudrate Divisor
OSCX1 Frequency
Input Clock Frequency e
UART Clock Divisor
Registers Divisor Latch Holds Baudrate Divisor
EF70 holds UART Clock Divisor
TL EE 12514 – 28
FIGURE 3-18 UART IRQ Timing
TL EE 12514 – 29
39
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