AT91SAM7S256C-MU Atmel, AT91SAM7S256C-MU Datasheet - Page 107

• Manufacturer Part Number: AT91SAM7S256C-MU
• Description: IC ARM7 MCU 32BIT 256K 64-QFN
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7S256C-MU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 64K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VQFN Exposed Pad, 64-HVQFN, 64-SQFN, 64-DHVQFN
• Processor Series: AT91
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 64 KB
• Interface Type: SPI, TWI, USART, USB
• Maximum Clock Frequency: 55 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 5
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7S-EK - KIT EVAL FOR ARM AT91SAM7S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: AT91SAM7S256-MU; AT91SAM7S256-MU

19.2.2
Figure 19-2. Code Read Optimization in Thumb Mode for FWS = 0
Note:
Figure 19-3. Code Read Optimization in Thumb Mode for FWS = 1
6175K–ATARM–30-Aug-10
ARM Request (16-bit)
ARM Request (16-bit)
Data To ARM
Data To ARM
Buffer (32 bits)
Flash Access
Buffer (32 bits)
Flash Access
Master Clock
Master Clock
Code Fetch
When FWS is equal to 0, all accesses are performed in a single-cycle access.
Code Fetch
Read Operations
@Byte 0
@Byte 0
1 Wait State Cycle
An optimized controller manages embedded Flash reads. A system of 2 x 32-bit buffers is added
in order to start access at following address during the second read, thus increasing perfor-
mance when the processor is running in Thumb mode (16-bit instruction set). See
Figure 19-3
This optimization concerns only Code Fetch and not Data.
The read operations can be performed with or without wait state. Up to 3 wait states can be pro-
grammed in the field FWS (Flash Wait State) in the Flash Mode Register MC_FMR (see
Flash Mode Register” on page
the embedded Flash.
The Flash memory is accessible through 8-, 16- and 32-bit reads.
As the Flash block size is smaller than the address space reserved for the internal memory area,
the embedded Flash wraps around the address space and appears to be repeated within it.
Bytes 0-3
@Byte 2
Bytes 0-1
Bytes 0-3
and
@Byte 2
Bytes 4-7
@Byte 4
Bytes 0-3
Bytes 2-3
Bytes 0-1
Figure
1 Wait State Cycle
19-4.
Bytes 4-5
@Byte 6
@Byte 4
Bytes 2-3
Bytes 4-7
Bytes 4-7
116). Defining FWS to be 0 enables the single-cycle access of
Bytes 0-3
AT91SAM7S Series Preliminary
Bytes 8-11
@Byte 8
@Byte 6
Bytes 6-7
Bytes 4-5
1 Wait State Cycle
@Byte 10
Bytes 8-9
@Byte 8
Bytes 6-7
Bytes 8-11
Bytes 8-11
Bytes 4-7
Bytes 12-15
Bytes 10-11
@Byte 10
@Byte 12
Bytes 8-9
1 Wait State Cycle
Bytes 12-13
Bytes 10-11
@Byte 12
@Byte 14
Bytes 12-15
Bytes 8-11
Bytes 12-15
Figure
Bytes 16-19
Bytes 12-13
Bytes 14-15
@Byte 14
@Byte 16
19-2,
“MC
107