Product Specs

Table Of Contents
9 AHB multilayer
Page
26
9
AHB multilayer
The CPU and all of the EasyDMAs are AHB bus masters on the AHB multilayer, while the RAM and various
other modules are AHB slaves.
See Block diagram on page 12 for an overview of which peripherals implement EasyDMA.
The CPU has exclusive access to all AHB slaves except for the RAM that can also be accessed by the
EasyDMA.
Access rights to each of the RAM AHB slaves are resolved using the priority of the different bus masters in
the system
See AHB multilayer priorities on page 26 for information about the priority of the different AHB bus
masters in the system. It is possible for two or more bus masters to have the same priority in cases where
it is guaranteed by design that the related masters will never be able to access the same slave at the same
time.
9.1 AHB multilayer priorities
Each master connected to the AHB multilayer is assigned a priority.
Table 11: AHB bus masters
Bus master name
Priority
Description
CPU
Highest priority
SPIS1
Applies to SPIM1, SPIS1, TWIM1, TWIS1
RADIO
CCM/ECB/AAR
SAADC
UARTE
SERIAL0
Applies to SPIM0, SPIS0, TWIM0, TWIS0
SERIAL2
Applies to SPIM2, SPIS2
NFCT
I2S
I2S
PDM
PDM
PWM
Lowest priority
Applies to PWM0, PWM1, PWM2