PM0020 datasheet(35/87 Pages) STMICROELECTRONICS

35 / 87 page

PM00020

STR91xFA Flash memory

35/87

1.15

FMI register description

The FMI Registers configure the size and base address of Bank 0 and Bank 1. The address

ranges of Bank 0 and Bank 1 must not overlap each other.

The microcontroller boots from Bank 0 by default:

In the default configuration:

●

Bank 0 is the Boot Bank, after reset the application program has to write the size and

base address of Bank 0 in the FMI_BBSR and FMI_BBADR registers

●

Bank 1 is the Non-Boot Bank, after reset the application program has to write the size

and base address of Bank 1 in the FMI_NBBSR and FMI_NBBADR registers

Booting from Bank 1

The STR91FA microcontroller can also boot from Bank 1. The selection of the Boot Bank

can be modified using JTAG.

If Bank 1 is the Boot bank, after reset, the application program has to write the size and start

address of Bank 1 in the FMI_BBSR and FMI_BBADR registers and the size and start

address of Bank 0 in the FMI_NBBSR and FMI_NBBADR registers.

1.15.1

Boot bank size register (FMI_BBSR)

Address: 5400 0000h

Reset value: 0000 0000h

Reserved

9876543210

Reserved

BBSIZE[3:0]

Bits 31:4

Reserved, always read as 0

Bits 3:0

BBSIZE[3:0]: Boot bank size

These bits are set and cleared by software. They define the address space for the

boot bank, Boot bank size = 2 BBSIZE[3:0] x 32Kbytes.

0000: 32 Kbytes.

0001: 64 Kbytes

....

1011: 64 Mbytes

Other values are reserved.

PM0020 Datasheet(PDF) 35 Page - STMicroelectronics