Data Sheet

Table Of Contents
Note: 
1. Pin group A (PA[7:0]), PF[6:2]), pin group B (PB[7:0], PC[7:0]), pin group C (PD:7:0, PE[3:0],
PF[1:0]). For 28-pin and 32-pin devices pin group A and B should be seen as a single group. The
combined continuous sink/source current for each individual group should not exceed the limits.
2. These parameters are for design guidance only and are not production tested.
4.11 USART
Figure 4-3. USART in SPI Mode - Timing Requirements in Master Mode
MSb LSb
t
MOS
t
MIS
t
MIH
t
SCKW
t
SCK
t
MOH
t
MOH
t
SCKF
t
SCKR
t
SCKW
MOSI
(Data Output)
MISO
(Data Input)
SCK
(CPOL = 1)
SCK
(CPOL = 0)
SS
MSb LSb
Table 4-17. USART in SPI Master Mode - Timing Characteristics
Symbol
(1)
Description Condition Min. Typ. Max. Unit
f
SCK
SCK clock frequency Master - - 10 MHz
t
SCK
SCK period Master 100 - - ns
t
SCKW
SCK high/low width Master - 0.5×t
SCK
- ns
t
SCKR
SCK rise time Master - 2.7 - ns
t
SCKF
SCK fall time Master - 2.7 - ns
t
MIS
MISO setup to SCK Master - 10 - ns
t
MIH
MISO hold after SCK Master - 10 - ns
t
MOS
MOSI setup to SCK Master - 0.5×t
SCK
- ns
t
MOH
MOSI hold after SCK Master - 1.0 - ns
Note: 
1. These parameters are for design guidance only and are not production tested.
ATmega809/1609/3209/4809 – 48-pin
Electrical Characteristics
© 2019 Microchip Technology Inc.
Datasheet Preliminary
DS40002016B-page 19