AT91M55800A-33CJ Atmel, AT91M55800A-33CJ Datasheet - Page 136

• Manufacturer Part Number: AT91M55800A-33CJ
• Description: IC ARM MCU 16BIT 176BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91M55800A-33CJ

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 33MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 58
• Program Memory Type: ROMless
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 176-LFBGA
• Processor Series: AT91Mx
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 8 KB
• Interface Type: EBI, SPI, USART
• Maximum Clock Frequency: 33 MHz
• Number Of Programmable I/os: 58
• Number Of Timers: 10 bit
• Operating Supply Voltage: 3 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91EB55
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• On-chip Dac: 8 bit, 2 Channel
• Cpu Family: AT91
• Device Core: ARM7TDMI
• Device Core Size: 32b
• Frequency (max): 33MHz
• Program Memory Size: Not Required
• Total Internal Ram Size: 8KB
• # I/os (max): 58
• Number Of Timers - General Purpose: 6
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 2.7V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 176
• Package Type: BGA
• For Use With: AT91EB55 - KIT EVAL FOR ARM AT91M55800A
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

18.2
Figure 18-2. Baud Rate Generator
136
MCK/8
MCK
SCK
Baud Rate Generator
AT91M5880A
USCLKS [0]
0
1
USCLKS [1]
The Baud Rate Generator provides the bit period clock (the Baud Rate clock) to both the
Receiver and the Transmitter.
The Baud Rate Generator can select between external and internal clock sources. The external
clock source is SCK. The internal clock sources can be either the master clock MCK or the mas-
ter clock divided by 8 (MCK/8).
Note:
When the USART is programmed to operate in Asynchronous Mode (SYNC = 0 in the Mode
Register US_MR), the selected clock is divided by 16 times the value (CD) written in US_BRGR
(Baud Rate Generator Register). If US_BRGR is set to 0, the Baud Rate Clock is disabled.
When the USART is programmed to operate in Synchronous Mode (SYNC = 1) and the selected
clock is internal (USCLKS[1] = 0 in the Mode Register US_MR), the Baud Rate Clock is the
internal selected clock divided by the value written in US_BRGR. If US_BRGR is set to 0, the
Baud Rate Clock is disabled.
In Synchronous Mode with external clock selected (USCLKS[1] = 1), the clock is provided
directly by the signal on the SCK pin. No division is active. The value written in US_BRGR has
no effect.
0
1
Baud Rate
Baud Rate
In all cases, if an external clock is used, the duration of each of its levels must be longer than the
system clock (MCK) period. The external clock frequency must be at least 2.5 times lower than the
system clock.
CLK
=
=
16-bit Counter
CD
Selected Clock
Selected Clock
16 x CD
CD
USCLKS [1]
SYNC
OUT
0
CD
>1
1
0
0
1
Divide
by 16
SYNC
0
1
1745F–ATARM–06-Sep-07
Baud Rate
Clock