C-Boot Rom Vector Table Map; C-Boot Rom Cpu Vector Table - Texas Instruments Concerto F28M35 Series Technical Reference Manual

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C-Boot ROM Vector Table

A CPU vector table resides in boot ROM memory from address 0x3F FFC0 - 0x3F FFFF. This vector table

is active after reset when VMAP = 1, ENPIE = 0 (PIE vector table disabled).

The VMAP bit is located in Status Register 1 (ST1). VMAP is always 1 on reset. It can be changed after reset by

software, however, the normal operating mode will be to leave VMAP=1.

The ENPIE bit is located in the PIECTRL register. The default state of this bit at reset is 0, which disables the

Peripheral Interrupt Expansion block (PIE).

The only vector that will normally be handled from the internal boot ROM memory is the reset vector

located at 0x3F FFC0. The reset vector is factory programmed to point to the InitBoot function stored in

the boot ROM. This function starts the boot load process.

PIE and all the peripheral interrupts are disabled by default on reset on the control subsystem. ITRAP and

NMI exceptions are enabled by default, so until PIE is enabled, the control subsystem CPU will fetch for

interrupt vector from the CPU vector table in C-Boot ROM for NMI, ITRAP or Reset exceptions as shown

For TI silicon debug and test purposes the interrupt vectors (not the NMI and ITRAP exceptions) located in

the boot ROM memory point to locations in the M0 SARAM block as described in below table. During

silicon debug, user can program the specified locations in M0 with branch instructions to catch any vectors

fetched from boot ROM. This is not required for normal device operation.

Vector Name (Number)

SPRUH22I – April 2012 – Revised November 2019

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Figure 6-11. C-Boot ROM Vector Table Map

Section Start

Reset Vector

CPU Vector Table

Table 6-16. C-Boot ROM CPU Vector Table

Vector Address or Location in

BootROM – When PIE is disabled

Reset fetched from here when

Other vectors fetched from

here when VMAP=1, ENPIE=0

Contents (Handler address)

ROM Code and Peripheral Booting

C-Boot ROM Description

Chapters

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