VMC — Volatile memory controller

The volatile memory controller (VMC) provides power control of RAM blocks.

Each of the available RAM blocks, which can contain multiple RAM sections, can be turned on or off independently in System ON mode, using the RAM[n]registers. These registers also control if a RAM block, or some of its sections, is retained in System OFF mode. See Memory chapter for more information about RAM blocks and sections.

Note: Powering up a RAM block takes typically 10 cycles. Thus, it is recommended reading the POWER register before accessing a RAM block that has been recently powered on.

Registers

Instances

InstanceBase addressTrustZoneSplit accessDescription
MapAttDMA

VMC : S
VMC : NS

0x5003A000
0x4003A000

USNSNANo

Volatile memory controller

Register overview

RegisterOffsetTZDescription
RAM[n].POWER0x600

RAMn power control register

RAM[n].POWERSET0x604

RAMn power control set register

RAM[n].POWERCLR0x608

RAMn power control clear register

RAM[n].POWER (n=0..7)

Address offset: 0x600 + (n × 0x10)

RAMn power control register

Bit number313029282726252423222120191817161514131211109876543210
IDHGFEDCBA
Reset 0x0000FFFF00000000000000001111111111111111
IDR/WFieldValue IDValueDescription
A-D

RW

S[i]POWER (i=0..3)

Keep RAM section Si of RAM n on or off in System ON mode

All RAM sections will be switched off in System OFF mode

Off

0

Off

On

1

On

E-H

RW

S[i]RETENTION (i=0..3)

Keep retention on RAM section Si of RAM n when RAM section is switched off

Off

0

Off

On

1

On

RAM[n].POWERSET (n=0..7)

Address offset: 0x604 + (n × 0x10)

RAMn power control set register

When read, this register will return the value of the POWER register.

Bit number313029282726252423222120191817161514131211109876543210
IDHGFEDCBA
Reset 0x0000FFFF00000000000000001111111111111111
IDR/WFieldValue IDValueDescription
A-D

W

S[i]POWER (i=0..3)

Keep RAM section Si of RAM n on or off in System ON mode

On

1

On

E-H

W

S[i]RETENTION (i=0..3)

Keep retention on RAM section Si of RAM n when RAM section is switched off

On

1

On

RAM[n].POWERCLR (n=0..7)

Address offset: 0x608 + (n × 0x10)

RAMn power control clear register

When read, this register will return the value of the POWER register.

Bit number313029282726252423222120191817161514131211109876543210
IDHGFEDCBA
Reset 0x0000FFFF00000000000000001111111111111111
IDR/WFieldValue IDValueDescription
A-D

W

S[i]POWER (i=0..3)

Keep RAM section Si of RAM n on or off in System ON mode

Off

1

Off

E-H

W

S[i]RETENTION (i=0..3)

Keep retention on RAM section Si of RAM n when RAM section is switched off

Off

1

Off