LM3S308 Luminary Micro, Inc, LM3S308 Datasheet - Page 110

• Manufacturer Part Number: LM3S308
• Description: Lm3s308 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Internal Memory
7
7.1
7.2
7.2.1
110
Internal Memory
The LM3S308 microcontroller comes with 4 KB of bit-banded SRAM and 16 KB of flash memory.
The flash controller provides a user-friendly interface, making flash programming a simple task.
Flash protection can be applied to the flash memory on a 2-KB block basis.
Block Diagram
Figure 7-1 on page 110 illustrates the Flash functions. The dashed boxes in the figure indicate
registers residing in the System Control module rather than the Flash Control module.
Figure 7-1. Flash Block Diagram
Functional Description
This section describes the functionality of the SRAM and Flash memories.
SRAM Memory
The internal SRAM of the Stellaris
map. To reduce the number of time consuming read-modify-write (RMW) operations, ARM has
introduced bit-banding technology in the Cortex-M3 processor. With a bit-band-enabled processor,
certain regions in the memory map (SRAM and peripheral space) can use address aliases to access
individual bits in a single, atomic operation.
The bit-band alias is calculated by using the formula:
bit-band alias = bit-band base + (byte offset * 32) + (bit number * 4)
For example, if bit 3 at address 0x2000.1000 is to be modified, the bit-band alias is calculated as:
SRAM Array
Cortex-M3
Bridge
Icode Bus
Dcode Bus
®
devices is located at address 0x2000.0000 of the device memory
Preliminary
Flash Protection
Flash Control
Flash Timing
USECRL
FCMISC
FMPRE
FMPPE
FCRIS
FCIM
FMD
FMC
FMA
Flash Array
June 04, 2008