Specifications

166
3706C–MICRO–2/11
AT89LP3240/6440
Figure 25-7. Serial Programming Power-up Sequence
25.9.2 Power-down Sequence
Execute this sequence to power-down the device after programming.
1. Drive SCK low.
2. Wait at least t
SSD
and bring SS high.
3. Tristate MOSI.
4. Wait at least t
SSZ
and then tristate SS and SCK.
5. Wait no more than t
PWRDN
and power off VDD.
Figure 25-8. Serial Programming Power-down Sequence
25.9.3 ISP Start Sequence
Execute this sequence to exit CPU execution mode and enter ISP mode when the device has
passed Power-On Reset and is already operational.
1. Drive RST
low.
2. Drive SS
high.
3. Wait t
RLZ
+ t
STL
.
4. Start programming session.
V
DD
RST
SS
SCK
HIGH ZMISO
HIGH ZMOSI
t
PWRUP
t
POR
+ t
SUT
t
ZSS
V
DD
RST
SS
SCK
HIGH ZMISO
HIGH ZMOSI
t
PWRDN
t
SSD
t
SSZ