beautypg.com

Serial programming characteristics, At89s51 – Rainbow Electronics АТ89С51 User Manual

Page 19

background image

19

AT89S51

2487A–10/01

Serial Programming Characteristics

Figure 9. Serial Programming Timing

MOSI

MISO

SCK

t

OVSH

t

SHSL

t

SLSH

t

SHOX

t

SLIV

Table 9. Serial Programming Characteristics, T

A

= -40

°

C to 85

°

C, V

CC

= 4.0 - 5.5V (Unless Otherwise Noted)

Symbol

Parameter

Min

Typ

Max

Units

1/t

CLCL

Oscillator Frequency

0

33

MHz

t

CLCL

Oscillator Period

30

ns

t

SHSL

SCK Pulse Width High

8 t

CLCL

ns

t

SLSH

SCK Pulse Width Low

8 t

CLCL

ns

t

OVSH

MOSI Setup to SCK High

t

CLCL

ns

t

SHOX

MOSI Hold after SCK High

2 t

CLCL

ns

t

SLIV

SCK Low to MISO Valid

10

16

32

ns

t

ERASE

Chip Erase Instruction Cycle Time

500

ms

t

SWC

Serial Byte Write Cycle Time

64 t

CLCL

+ 400

µs