ST7LITEU09 STMicroelectronics, ST7LITEU09 Datasheet - Page 66

• Manufacturer Part Number: ST7LITEU09
• Description: ST7ULTRALITE - 8-BIT MCU WITH 2K SINGLE VOLTAGE FLASH MEMORY, ADC, TIMERS
• Manufacturer: STMicroelectronics

Specifications of ST7LITEU09

• 2k Bytes Single Voltage Flash Program Memory With Read-out Protection, In-circuit And In-application Programming (icp And Iap). 10k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55°C
• 128 Bytes Data Eeprom. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55°C
• Clock Sources: internal trimmable 8MHz RC oscillator, internal low power, low frequency RC oscillator or external clock
• Five Power Saving Modes: Halt, Auto Wake Up from Halt, Active-Halt, Wait and Slow
• One 8-bit Lite Timer (lt) With Prescaler Including: watchdog, 1 realtime base and 1 input capture

I/O ports
10.3
10.4
Table 22.
10.5
10.6
66/139
Wait
Halt
Mode
Unused I/O pins
Unused I/O pins must be connected to fixed voltage levels. Refer to
109.
Low power modes
Effect of low power modes on I/O ports
Interrupts
The external interrupt event generates an interrupt if the corresponding configuration is
selected with DDR and OR registers and the interrupt mask in the CC register is not active
(RIM instruction).
Table 23.
I/O port implementation
The hardware implementation on each I/O port depends on the settings in the DDR and OR
registers and specific feature of the I/O port such as ADC Input or true open drain.
Switching these I/O ports from one state to another should be done in a sequence that
prevents unwanted side effects. Recommended safe transitions are illustrated in
Other transitions are potentially risky and should be avoided, since they are likely to present
unwanted side-effects such as spurious interrupt generation.
Figure 33. Interrupt I/O port state transitions
External interrupt on selected
external event
No effect on I/O ports. External interrupts cause the device to exit from Wait mode.
No effect on I/O ports. External interrupts cause the device to exit from Halt mode.
Interrupt event
Description of interrupt events
floating/pull-up
interrupt
INPUT
01
(reset state)
Event
floating
INPUT
flag
00
-
Description
open-drain
OUTPUT
10
XX
Enable
control
DDRx
ORx
bit
= DDR, OR
OUTPUT
push-pull
11
ST7LITEU05 ST7LITEU09
Section 13.8 on page
from
Wait
Exit
Yes
Figure
from
Exit
Halt
Yes
33.