ATMEGA48-20MMU Atmel, ATMEGA48-20MMU Datasheet - Page 205

IC AVR MCU 4K FLASH 20MHZ 28QFN

ATMEGA48-20MMU

Manufacturer Part Number
ATMEGA48-20MMU
Description
IC AVR MCU 4K FLASH 20MHZ 28QFN
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets

Specifications of ATMEGA48-20MMU

Core Processor
AVR
Core Size
8-Bit
Speed
20MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
23
Program Memory Size
4KB (2K x 16)
Program Memory Type
FLASH
Eeprom Size
256 x 8
Ram Size
512 x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
Processor Series
ATMEGA48x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
512 B
Interface Type
2-Wire/SPI/USART/Serial
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
23
Number Of Timers
3
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
On-chip Adc
8-ch x 10-bit
Package
28MLF EP
Device Core
AVR
Family Name
ATmega
Maximum Speed
20 MHz
Operating Supply Voltage
3.3|5 V
For Use With
ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
20.8
20.8.1
20.8.2
20.8.3
2545S–AVR–07/10
Register Description
UDRn – USART MSPIM I/O Data Register
UCSRnA – USART MSPIM Control and Status Register n A
UCSRnB – USART MSPIM Control and Status Register n B
The following section describes the registers used for SPI operation using the USART.
The function and bit description of the USART data register (UDRn) in MSPI mode is identical to
normal USART operation. See “UDRn – USART I/O Data Register n” on page 189.
• Bit 7 - RXCn: USART Receive Complete
This flag bit is set when there are unread data in the receive buffer and cleared when the receive
buffer is empty (that is, does not contain any unread data). If the Receiver is disabled, the
receive buffer will be flushed and consequently the RXCn bit will become zero. The RXCn Flag
can be used to generate a Receive Complete interrupt (see description of the RXCIEn bit).
• Bit 6 - TXCn: USART Transmit Complete
This flag bit is set when the entire frame in the Transmit Shift Register has been shifted out and
there are no new data currently present in the transmit buffer (UDRn). The TXCn Flag bit is auto-
matically cleared when a transmit complete interrupt is executed, or it can be cleared by writing
a one to its bit location. The TXCn Flag can generate a Transmit Complete interrupt (see
description of the TXCIEn bit).
• Bit 5 - UDREn: USART Data Register Empty
The UDREn Flag indicates if the transmit buffer (UDRn) is ready to receive new data. If UDREn
is one, the buffer is empty, and therefore ready to be written. The UDREn Flag can generate a
Data Register Empty interrupt (see description of the UDRIE bit). UDREn is set after a reset to
indicate that the Transmitter is ready.
• Bit 4:0 - Reserved Bits in MSPI mode
When in MSPI mode, these bits are reserved for future use. For compatibility with future devices,
these bits must be written to zero when UCSRnA is written.
• Bit 7 - RXCIEn: RX Complete Interrupt Enable
Writing this bit to one enables interrupt on the RXCn Flag. A USART Receive Complete interrupt
will be generated only if the RXCIEn bit is written to one, the Global Interrupt Flag in SREG is
written to one and the RXCn bit in UCSRnA is set.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
RXCn
R
7
0
RXCIEn
R/W
7
0
TXCn
R/W
6
0
TXCIEn
R/W
6
0
UDREn
R
5
0
UDRIE
R/W
5
0
R
4
0
-
RXENn
R/W
4
0
R
3
0
-
TXENn
R/W
3
0
R
2
1
-
ATmega48/88/168
R
2
1
-
R
1
1
-
R
1
1
-
R
0
0
-
R
0
0
-
UCSRnB
UCSRnA
205

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