Memory

The application microcontroller has embedded 1024 kB flash and 256 kB RAM for application code and data storage.

As illustrated in Memory layout, both CPU and EasyDMA are able to access RAM via the AHB multilayer interconnect. See AHB multilayer interconnect and EasyDMA for more information about AHB multilayer interconnect and EasyDMA respectively. The LTE modem can access all application MCU memory, but typically a small portion of RAM is dedicated to data exchange between application MCU and the modem baseband controller.

Figure 1. Memory layout

RAM - Random access memory

RAM can be read and written an unlimited number of times by the CPU and the EasyDMA.

Each RAM AHB slave is connected to one or more RAM sections. See Memory layout for more information.

The RAM blocks power states and retention states in System ON and System OFF modes are controlled by the VMC.

Flash - Non-volatile memory

Flash can be read an unlimited number of times by the CPU and is accessible via the AHB interface connected to the CPU, see Memory layout for more information. There are restrictions on the number of times flash can be written and erased, and also on how it can be written. For more information, see Absolute maximum ratings. Writing to flash is managed by the non-volatile memory controller (NVMC).

Memory map

All memory and registers are found in the same address space, as illustrated in the device memory map below.

Figure 2. Memory map

Some of the registers are retained (their values kept). Read more about retained registers in Retained registers and Reset behavior.

Instantiation

Table 1. Instantiation table
ID	Base address	Instance	TrustZone			Split access	Description
ID	Base address	Instance	Map	Att	DMA	Split access	Description
3	0x50003000	SPU	HF	S	NA	No	System Protection Unit
4	0x50004000 0x40004000	REGULATORS : S REGULATORS : NS	US	NS	NA	No	Regulator configuration
5	0x50005000 0x40005000	CLOCK : S CLOCK : NS	US	NS	NA	No	Clock control
5	0x50005000 0x40005000	POWER : S POWER : NS	US	NS	NA	No	Power control
6	0x50006000	CTRL_AP_PERI	HF	S	NA	No	CTRL-AP-PERI
8	0x50008000 0x40008000	SPIM0 : S SPIM0 : NS	US	NS	SA	No	SPI master 0
8	0x50008000 0x40008000	SPIS0 : S SPIS0 : NS	US	NS	SA	No	SPI slave 0
8	0x50008000 0x40008000	TWIM0 : S TWIM0 : NS	US	NS	SA	No	Two-wire interface master 0
8	0x50008000 0x40008000	TWIS0 : S TWIS0 : NS	US	NS	SA	No	Two-wire interface slave 0
8	0x50008000 0x40008000	UARTE0 : S UARTE0 : NS	US	NS	SA	No	Universal asynchronous receiver/transmitter with EasyDMA 0
9	0x50009000 0x40009000	SPIM1 : S SPIM1 : NS	US	NS	SA	No	SPI master 1
9	0x50009000 0x40009000	SPIS1 : S SPIS1 : NS	US	NS	SA	No	SPI slave 1
9	0x50009000 0x40009000	TWIM1 : S TWIM1 : NS	US	NS	SA	No	Two-wire interface master 1
9	0x50009000 0x40009000	TWIS1 : S TWIS1 : NS	US	NS	SA	No	Two-wire interface slave 1
9	0x50009000 0x40009000	UARTE1 : S UARTE1 : NS	US	NS	SA	No	Universal asynchronous receiver/transmitter with EasyDMA 1
10	0x5000A000 0x4000A000	SPIM2 : S SPIM2 : NS	US	NS	SA	No	SPI master 2
10	0x5000A000 0x4000A000	SPIS2 : S SPIS2 : NS	US	NS	SA	No	SPI slave 2
10	0x5000A000 0x4000A000	TWIM2 : S TWIM2 : NS	US	NS	SA	No	Two-wire interface master 2
10	0x5000A000 0x4000A000	TWIS2 : S TWIS2 : NS	US	NS	SA	No	Two-wire interface slave 2
10	0x5000A000 0x4000A000	UARTE2 : S UARTE2 : NS	US	NS	SA	No	Universal asynchronous receiver/transmitter with EasyDMA 2
11	0x5000B000 0x4000B000	SPIM3 : S SPIM3 : NS	US	NS	SA	No	SPI master 3
11	0x5000B000 0x4000B000	SPIS3 : S SPIS3 : NS	US	NS	SA	No	SPI slave 3
11	0x5000B000 0x4000B000	TWIM3 : S TWIM3 : NS	US	NS	SA	No	Two-wire interface master 3
11	0x5000B000 0x4000B000	TWIS3 : S TWIS3 : NS	US	NS	SA	No	Two-wire interface slave 3
11	0x5000B000 0x4000B000	UARTE3 : S UARTE3 : NS	US	NS	SA	No	Universal asynchronous receiver/transmitter with EasyDMA 3
13	0x5000D000	GPIOTE0	HF	S	NA	No	Secure GPIO tasks and events
14	0x5000E000 0x4000E000	SAADC : S SAADC : NS	US	NS	SA	No	Analog to digital converter
15	0x5000F000 0x4000F000	TIMER0 : S TIMER0 : NS	US	NS	NA	No	Timer 0
16	0x50010000 0x40010000	TIMER1 : S TIMER1 : NS	US	NS	NA	No	Timer 1
17	0x50011000 0x40011000	TIMER2 : S TIMER2 : NS	US	NS	NA	No	Timer 2
20	0x50014000 0x40014000	RTC0 : S RTC0 : NS	US	NS	NA	No	Real time counter 0
21	0x50015000 0x40015000	RTC1 : S RTC1 : NS	US	NS	NA	No	Real time counter 1
23	0x50017000 0x40017000	DPPIC : S DPPIC : NS	HF	NS	NA	Yes	DPPI configuration
24	0x50018000 0x40018000	WDT : S WDT : NS	US	NS	NA	No	Watchdog timer
27	0x5001B000 0x4001B000	EGU0 : S EGU0 : NS	US	NS	NA	No	Event generator unit 0
28	0x5001C000 0x4001C000	EGU1 : S EGU1 : NS	US	NS	NA	No	Event generator unit 1
29	0x5001D000 0x4001D000	EGU2 : S EGU2 : NS	US	NS	NA	No	Event generator unit 2
30	0x5001E000 0x4001E000	EGU3 : S EGU3 : NS	US	NS	NA	No	Event generator unit 3
31	0x5001F000 0x4001F000	EGU4 : S EGU4 : NS	US	NS	NA	No	Event generator unit 4
32	0x50020000 0x40020000	EGU5 : S EGU5 : NS	US	NS	NA	No	Event generator unit 5
33	0x50021000 0x40021000	PWM0 : S PWM0 : NS	US	NS	SA	No	Pulse width modulation unit 0
34	0x50022000 0x40022000	PWM1 : S PWM1 : NS	US	NS	SA	No	Pulse width modulation unit 1
35	0x50023000 0x40023000	PWM2 : S PWM2 : NS	US	NS	SA	No	Pulse width modulation unit 2
36	0x50024000 0x40024000	PWM3 : S PWM3 : NS	US	NS	SA	No	Pulse width modulation unit 3
38	0x50026000 0x40026000	PDM : S PDM : NS	US	NS	SA	No	Pulse density modulation (digital microphone) interface
40	0x50028000 0x40028000	I2S : S I2S : NS	US	NS	SA	No	Inter-IC Sound
42	0x5002A000 0x4002A000	IPC : S IPC : NS	US	NS	NA	No	Interprocessor communication
44	0x4002C000	FPU	HF	NS	NA	No	Floating-point unit
49	0x40031000	GPIOTE1	HF	NS	NA	No	Non Secure GPIO tasks and events
57	0x50039000 0x40039000	APPROTECT : S APPROTECT : NS	HF	NS	NA	Yes	APPROTECT control
57	0x50039000 0x40039000	KMU : S KMU : NS	HF	NS	NA	Yes	Key management unit
57	0x50039000 0x40039000	NVMC : S NVMC : NS	HF	NS	NA	Yes	Non-volatile memory controller
58	0x5003A000 0x4003A000	VMC : S VMC : NS	US	NS	NA	No	Volatile memory controller
64	0x50840000	CC_HOST_RGF	HF	S	NSA	No	Host platform interface
64	0x50840000	CRYPTOCELL	HF	S	NSA	No	CryptoCell sub-system control interface
66	0x50842500 0x40842500	P0 : S P0 : NS	HF	NS	NA	Yes	General purpose input and output
N/A	0x00FF0000	FICR	HF	S	NA	No	Factory information configuration
N/A	0x00FF8000	UICR	HF	S	NA	No	User information configuration
N/A	0xE0041000	ETM	HF	NS	NA	No	ETM
N/A	0xE0051000	ETB	HF	NS	NA	No	ETB
N/A	0xE0054000	TPIU	HF	NS	NA	No	TPIU
N/A	0xE0058000	ATBREPLICATOR	HF	NS	NA	No	ATBREPLICATOR
N/A	0xE005A000	ATBFUNNEL1	HF	NS	NA	No	ATBFUNNEL unit 1
N/A	0xE005B000	ATBFUNNEL2	HF	NS	NA	No	ATBFUNNEL unit 2
N/A	0xE0080000	TAD	HF	S	NA	No	Trace and debug control

Peripheral access control capabilities

Information about the peripheral access control capabilities can be found in the instantiation table.

The instantiation table has two columns containing the information about access control capabilities for a peripheral:

Secure mapping: This column defines configuration capabilities for TrustZone®-M secure attribute.
DMA security: This column indicates whether the peripheral has DMA capabilities, and if DMA transfer can be assigned to a different security attribute than the peripheral itself.

For details on options in secure mapping column and DMA security column, see the following tables respectively.

Table 2. Secure mapping column options
Abbreviation	Description
NS	Non-secure: This peripheral is always accessible as a non-secure peripheral.
S	Secure: This peripheral is always accessible as a secure peripheral.
US	User-selectable: Non-secure or secure attribute for this peripheral is defined by the PERIPHID[0].PERM register.
SPLIT	Both non-secure and secure: The same resource is shared by both secure and non-secure code.

Table 3. DMA security column options
Abbreviation	Description
NA	Not applicable: Peripheral has no DMA capability.
NSA	No separate attribute: Peripheral has DMA, and DMA transfers always have the same security attribute as assigned to the peripheral.
SA	Separate attribute: Peripheral has DMA, and DMA transfers can have a different security attribute than the one assigned to the peripheral.