ST7LITE49K2 STMicroelectronics, ST7LITE49K2 Datasheet - Page 118

• 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

On-chip peripherals
Note:
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16-bit read sequence (from either the counter register or the alternate counter register)
Figure 56. 16-bit read sequence
The user must read the MSB first, then the LSB value is buffered automatically.
This buffered value remains unchanged until the 16-bit read sequence is completed, even if
the user reads the MSB several times.
After a complete reading sequence, if only the CLR register or ACLR register are read, they
return the LSB of the count value at the time of the read.
Whatever the timer mode used (input capture, output compare, one pulse mode or PWM
mode) an overflow occurs when the counter rolls over from FFFFh to 0000h then:
●
●
If one of these conditions is false, the interrupt remains pending to be issued as soon as
they are both true.
Clearing the overflow interrupt request is done in two steps:
1.
2.
The TOF bit is not cleared by accesses to ACLR register. The advantage of accessing the
ACLR register rather than the CLR register is that it allows simultaneous use of the overflow
function and reading the free running counter at random times (for example, to measure
elapsed time) without the risk of clearing the TOF bit erroneously.
The timer is not affected by Wait mode.
In Halt mode, the counter stops counting until the mode is exited. Counting then resumes
from the previous count (device awakened by an interrupt) or from the reset count (device
awakened by a reset).
External clock
The external clock (where available) is selected if CC0 = 1 and CC1 = 1 in CR2 register.
The status of the EXEDG bit in the CR2 register determines the type of level transition on
the external clock pin EXTCLK that triggers the free running counter.
The counter is synchronized with the falling edge of the internal CPU clock.
The TOF bit of the SR register is set.
A timer interrupt is generated if:
–
–
Reading the SR register while the TOF bit is set.
An access (read or write) to the CLR register.
TOIE bit of the CR1 register is set and
I bit of the CC register is cleared.
Beginning of the sequence
Sequence completed
At t0 +Δt
At t0
Read MSB
instructions
Read LSB
Other
Returns the buffered
LSB is buffered
LSB value at t0
ST7LITE49K2