ST STM8S Reference Manual

Flash program memory and data EEPROM RM0016
36/449 Doc ID 14587 Rev 8
4.4 Memory organization
4.4.1 STM8S and STM8A memory organization
STM8S and STM8A EEPROM is organized in 32-bit words (4 bytes per word).
The memory organization differs according to the devices:
● Low density STM8S devices
– 8 Kbytes of Flash program memory organized in 128 pages or blocks of 64 bytes
each. The Flash program memory is divided into 2 areas, the user boot code area
(UBC), which size can be configured by option byte, and the main program
memory area. The Flash program memory is mapped in the upper part of the
STM8S addressing space and includes the reset and interrupt vectors.
– Up to 640 bytes of data EEPROM (DATA) organized in pages or blocks of 64 bytes
each. One block (64 bytes) contains the option bytes of which 11 are used to
configure the device hardware features. The options bytes can be programmed in
user, IAP and ICP/SWIM modes.
● Medium density STM8S devices
– From 16 to 32 Kbytes of Flash program memory organized in up to 64 pages of 4
blocks of 128 bytes each. The Flash program memory is divided into 2 areas, the
user boot code area (UBC), which size can be configured by option byte, and the
main program memory area. The Flash program memory is mapped in the upper
part of the STM8S addressing space and includes the reset and interrupt vectors.
– Up to 1 Kbyte of data EEPROM (DATA) organized in up to 2 pages of 4 blocks of
128 bytes each. One block (128 bytes) contains the option bytes of which 13 are
used to configure the device hardware features. The options bytes can be
programmed in user, IAP and ICP/SWIM modes.
● Medium density STM8A devices
– From 8 to 32 Kbytes of Flash program memory organized in up to 64 pages of 4
blocks of 128 bytes each. The Flash program memory is divided into 2 areas, the
user boot code area (UBC), which size can be configured by option byte, and the
main program memory area. The Flash program memory is mapped in the upper
part of the STM8A addressing space and includes the reset and interrupt vectors.
– Up to 1 Kbyte of data EEPROM (DATA) organized in up to 2 pages of 4 blocks of
128 bytes each. One block (128 bytes) contains the option bytes of which 13 are
used to configure the device hardware features. The options bytes can be
programmed in user, IAP and ICP/SWIM modes.
● High density STM8S devices
– From 32 to 128 Kbytes of Flash program memory organized in up to 256 pages of
4 blocks of 128 bytes each. The Flash program memory is divided into 2 areas, the
user boot code area (UBC), which size can be configured by option byte, and the
main program memory area. The Flash program memory is mapped in the upper
part of the STM8S addressing space and includes the reset and interrupt vectors.
– Up to 2 Kbytes of data EEPROM (DATA) organized in up to 4 pages of 4 blocks of
128 bytes each. The size of the DATA area is fixed for a given microcontroller. One
block (128 bytes) contains the option bytes of which 15 are used to configure the

ST STM8S Specifications

General

Brand	ST
Model	STM8S
Category	Microcontrollers
Language	English