37.1 Rev.B - 12/2021

Section	Changes
Document	Data sheet status changed to “Completed”: final limits added to the Electrical Characteristics, Typical Characteristics expanded, and package top markings added Editorial updates throughout the document
CPUINT	Description of the IVSEL bit in the CTRLA register improved: When the entire Flash is configured as BOOT section, the IVSEL bit in the CTRLA register is ignored.
PORT	Slew rate limitation functionality added: Slew Rate Limit Enable (SLR) bit in the Port Control (PORTCTRL) register.
USART	Description of the IREI bit in the EVCTRL register corrected
TWI	CTRLA.SDASETUP is used in client mode to select the clock hold time to ensure minimum setup time
ADC	PGA initialization time is 20 µs
Electrical Characteristics	Table 33-5: Typical values altered and min./max. values added Table 33-6: Completed Table 33-7: ADC updated Table 33-12: Note added Table 33-13: Note added Table 33-22: Symbol column updated Table 33-23: Value set reduced and updated ADC Table 33-26: values updated ADC Table 33-27: Values updated ADC Table 33-28: Values updated TEMPSENSE Table 33-29: Accuracy value updated AC: Typical values altered and min./max. values added in all tables
Typical Characteristics	Plots added

Document

Data sheet status changed to “Completed”: final limits added to the Electrical Characteristics, Typical Characteristics expanded, and package top markings added
Editorial updates throughout the document

CPUINT

Description of the IVSEL bit in the CTRLA register improved: When the entire Flash is configured as BOOT section, the IVSEL bit in the CTRLA register is ignored.

PORT

Slew rate limitation functionality added: Slew Rate Limit Enable (SLR) bit in the Port Control (PORTCTRL) register.

USART

Description of the IREI bit in the EVCTRL register corrected

TWI

CTRLA.SDASETUP is used in client mode to select the clock hold time to ensure minimum setup time

ADC

PGA initialization time is 20 µs

Electrical Characteristics

Table 33-5: Typical values altered and min./max. values added
Table 33-6: Completed
Table 33-7: ADC updated
Table 33-12: Note added
Table 33-13: Note added
Table 33-22: Symbol column updated
Table 33-23: Value set reduced and updated
ADC Table 33-26: values updated
ADC Table 33-27: Values updated
ADC Table 33-28: Values updated
TEMPSENSE Table 33-29: Accuracy value updated
AC: Typical values altered and min./max. values added in all tables

Typical Characteristics

Plots added

ATtiny424/426/427 ATtiny824/826/827

37.1 Rev.B - 12/2021