
Memory and bus architecture
RM0453
60/1454
RM0453 Rev 2
2
Memory and bus architecture
The following definitions are used in this section:
•
CPU1 = Arm Cortex-M4 with MPU and DSP
•
CPU2 = Arm Cortex-M0+ with MPU
When ESE = 0, CPU2 is non-secure. When ESE = 1, CPU2 is secure.
2.1 System
architecture
The main system consists of a 32-bit multilayer AHB bus matrix that interconnects the
following masters and slaves:
•
Six masters:
–
CPU1 core I-bus
–
CPU1 core D-bus
–
CPU1 core S-bus
–
CPU2 core S-bus
–
DMA1
–
DMA2
•
Eight slaves:
–
Internal Flash memory on the CPU1 Code bus
–
Internal Flash memory on CPU1 DCode bus
–
Internal Flash memory on CPU2 S bus
–
Internal SRAM1 (32 Kbytes)
–
Internal SRAM2 (32 Kbytes)
–
AHB1 peripherals including AHB to APB bridges and APB peripherals (connected
to APB1 and APB2)
–
AHB2 peripherals
–
AHB3 peripherals including AHB to APB bridges and APB peripherals (connected
to APB3)
The bus matrix provides access from a master to a slave, enabling concurrent access and
efficient operation even when several high-speed peripherals work simultaneously.