Datasheet

46
3286P–MICRO–3/10
AT89S8253
27. Serial Downloading Waveforms (SPI Mode 1 −−> CPOL = 0, CPHA = 1)
28. Serial Programming Characteristics
Figure 28-1. Serial Programming Timing
Table 28-1. Serial Programming Characteristics, T
A
= -40° C to 85° C, V
CC
= 2.7V - 5.5V (Unless Otherwise Noted)
Symbol Parameter Min Typ Max Units
1/t
CLCL
Oscillator Frequency 3 24 MHz
t
CLCL
Oscillator Period 41.6 33.3 ns
t
SHSL
SCK Pulse Width High 8 t
CLCL
ns
t
SLSH
SCK Pulse Width Low 8 t
CLCL
ns
t
OVSL
MOSI Setup to SCK Low t
CLCL
ns
t
SHOX
MOSI Hold after SCK Low 2 t
CLCL
ns
t
SHIV
SCK High to MISO Valid 10 16 32 ns
t
ERASE
Chip Erase Instruction Cycle Time 9 ms
t
SWC
Serial Page Write Cycle Time 4.5 ms
SERIAL DATA INPUT
SCK/P1.7
MOSI/P1.5
MISO/P1.6
SERIAL DATA OUTPUT
0
1
2
3
4
5
6
7
MSB
MSB
LSB
LSB
SCK
MISO
MOSI
t
OVSL
SHIV
t
SHSL
t
SLSH
t
SHOX
t
Change
Outputs
Sample
Inputs