ST7LITE49K2 STMicroelectronics, ST7LITE49K2 Datasheet - Page 65

• Manufacturer Part Number: ST7LITE49K2
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST7LITE49K2

• 8 Kbytes Single Voltage Extended Flash (xflash) Program Memory With Read-out Protection In-circuit Programming And In-application Programming (icp And Iap) Endurance: 10K write/erase cycles guaranteed Data retention
• 256 Bytes Data Eeprom With Read-out Protection. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55 °C.
• Clock Sources: Internal trimmable 8 MHz RC oscillator, auto-wakeup internal low power - low frequency oscillator, crystal/ceramic resonator or external clock
• Five Power Saving Modes: Halt, Active-halt, Auto-wakeup from Halt, Wait and Slow

ST7LITE49K2
9.4
Figure 26. Wait mode flowchart
1. Before servicing an interrupt, the CC register is pushed on the stack. The I bit of the CC register is set
Active-halt and Halt modes
Active-Halt and Halt modes are the two lowest power consumption modes of the MCU. They
are both entered by executing the ‘HALT’ instruction. The decision to enter either in Active-
Halt or Halt mode is given by the LTCSR/ATCSR register status as shown in the following
table:
Table 20.
LTCSR TBIE
during the interrupt routine and cleared when the CC register is popped.
bit
0
0
0
1
x
Enabling/disabling Active-halt and Halt modes
ATCSR OVFIE
bit
0
1
1
x
x
WFI INSTRUCTION
N
ATCSRCK1 bit ATCSRCK0 bit
INTERRUPT
Y
x
x
1
x
0
OR SERVICE INTERRUPT
FETCH RESET VECTOR
256 CPU CLOCK CYCLE
OSCILLATOR
PERIPHERALS
CPU
I BIT
OSCILLATOR
PERIPHERALS
CPU
I BIT
OSCILLATOR
PERIPHERALS
CPU
I BIT
N
DELAY
RESET
Y
0
1
1
x
x
OFF
OFF
X
ON
ON
ON
ON
ON
ON
ON
0
0
1)
Active-halt mode disabled
Active-halt mode enabled
Power saving modes
Meaning
65/245