ATSAM3U1CB-AU Datasheet, PDF (6/60 Pages) ATMEL Corporation – AT91SAM ARM-based Flash MCU

Table 3-1. Signal Description List (Continued)
Signal Name
Function
Type
Active
Level
Voltage
Reference Comments
Flash Memory
ERASE
Flash and NVM Configuration Bits Erase
Command
Input
High
VDDBU Internal permanent 15K
pulldown
Reset/Test
NRST
Microcontroller Reset
I/O
Low
VDDIO
Internal permanent
pullup
NRSTB
TST
Asynchronous Microcontroller Reset
Test Select
Input
Input
Low
Internal permanent
pullup
VDDBU
Internal permanent
pulldown
Universal Asynchronous Receiver Transceiver - UART
URXD
UART Receive Data
Input
UTXD
UART Transmit Data
Output
PA0 - PA31
PIO Controller - PIOA - PIOB - PIOC
Parallel IO Controller A
I/O
PB0 - PB31
Parallel IO Controller B
I/O
PC0 - PC31
Parallel IO Controller C
I/O
VDDIO
•Schmitt Trigger ⁽¹⁾
Reset State:
•PIO Input
•Internal pullup enabled
•Schmitt Trigger ⁽²⁾
Reset State:
•PIO Input
•Internal pullup enabled
•Schmitt Trigger⁽³⁾
Reset State:
•PIO Input
•Internal pullup enabled
External Bus Interface
D0 - D15
Data Bus
I/O
A0 - A23
Address Bus
Output
NWAIT
External Wait Signal
Input
Low
Static Memory Controller - SMC
NCS0 - NCS3
Chip Select Lines
Output
Low
NWR0 - NWR1
Write Signal
Output
Low
NRD
Read Signal
Output
Low
NWE
Write Enable
Output
Low
NBS0 - NBS1
Byte Mask Signal
Output
Low
NAND Flash Controller - NFC
NANDOE
NAND Flash Output Enable
Output
Low
NANDWE
NAND Flash Write Enable
Output
Low
NANDRDY
NAND Ready
Input
6 SAM3U Series
6430FS–ATARM–10-Feb-12