CMSIS-SVD  Version 1.10
CMSIS System View Description
registerPropertiesGroup

Register properties can be set on device, peripheral, and register level. Element values defined on a lower level overwrite element values defined on a more general level. For example, the register-level.<size> will overwrite peripheral-level.<size>. Elements that have not been defined on a more general level, must be defined at register level at the latest.

Element Name Description Type Occurrence
size Defines the default bit-width of any register contained in the device (implicit inheritance). This element can be redefined on any lower level of the description using the size element there. scaledNonNegativeInteger 0..1
access Defines the default access rights for all registers. Access rights can be redefined on any lower level of the description using the access element there.

The predefined tokens are:
  • read-only: read access is permitted. Write operations have an undefined result.
  • write-only: write access is permitted. Read operations have an undefined result.
  • read-write: both read and write accesses are permitted. Writes affect the state of the register and reads return a value related to the register.
  • writeOnce: only the first write after reset has an effect on the register. Read operations deliver undefined results.
  • read-writeOnce: Read operations deliver a result related to the register content. Only the first write access to this register after a reset will have an effect on the register content.
accessType 0..1
resetValue Defines the default value for all registers at RESET. The default register value can be redefined on any lower level using the resetValue element there. The actual reset value is calculated from the resetValue and the resetMask. The mask is used to specify bits with an undefined reset value. scaledNonNegativeInteger 0..1
resetMask Identifies which register bits have a defined reset value. These bit positions are set to one. Bit positions with an undefined reset value are set to zero. scaledNonNegativeInteger 0..1