AC Switching Characteristics

READ TIMING DATA FROM PERIPHERAL TO MICROPROCESSOR

Symbol

Parameter

Commercial Specification

Units

Min

Typ

Max

Address Bus Valid to Data Valid

390

650

ns

Chip Select On to Data Valid

140

300

ns

Read Strobe On to Data Valid

140

300

ns

Read Strobe Width (Note 3 Note 7)

300

DC

ns

Address Bus Hold Time from Trailing

0ns

Edge of Read Strobe

Chip Select Hold Time from Trailing

0ns

Edge of Read Strobe

Data Hold Time from Trailing

70

160

ns

Edge of Read Strobe

Time from Trailing Edge of Read Strobe

250

ns

Unitl OP Drivers are TRI-STATE

WRITE TIMING DATA FROM MICROPROCESSOR TO PERIPHERAL

Symbol

Parameter

Commercial Specification

Units

Min

Typ

Max

Address Bus Valid to Write Strobe

O

400

125

ns

(Note 4 Note 6)

Chip Select On to Write Strobe

O

250

100

ns

Data Bus Valid to Write Strobe

O

400

220

ns

Write Strobe Width (Note 6)

250

95

ns

Chip Select Hold Time Following

0ns

Write Strobe

O

Address Bus Hold Time Following

0ns

Write Strobe

O

Data Bus Hold Time Following

100

35

ns

Write Strobe

O

Address Bus Valid before

70

20

ns

Start or Write Strobe

Note 3

Except for special case restriction with interrupts programmed max read strobe width of control register (ADDR 0) is 30 ms See section on Interrupt

Programming

Note 4

All timings measured to the trailing edge of write strobe (data latched by the trailing edge of WR)

Note 5

Input test waveform peak voltages are 24V and 04V Output signals are measured to their 24V and 04V levels

Note 6

strobe commences when both signals are low and terminates when the first signal returns high

Note 7

Note 8

3