Documentation Conventions; List Of Abbreviations For Registers - ST STM32F40 Series Reference Manual

Documentation conventions

1 Documentation conventions
The Cortex-M4 core with FPU will be referred to as Cortex-M4F throughout this document.
1.1

List of abbreviations for registers

The following abbreviations are used in register descriptions:
read/write (rw)
read-only (r)
write-only (w)
read/clear (rc_w1) Software can read as well as clear this bit by writing 1. Writing '0' has
read/clear (rc_w0) Software can read as well as clear this bit by writing 0. Writing '1' has
read/clear by read
(rc_r)
read/set (rs)
read-only write
trigger (rt_w)
toggle (t)
Reserved (Res.)
47/1422
Software can read and write to these bits.
Software can only read these bits.
Software can only write to this bit. Reading the bit returns the reset
value.
no effect on the bit value.
no effect on the bit value.
Software can read this bit. Reading this bit automatically clears it to '0'.
Writing '0' has no effect on the bit value.
Software can read as well as set this bit. Writing '0' has no effect on the
bit value.
Software can read this bit. Writing '0' or '1' triggers an event but has no
effect on the bit value.
Software can only toggle this bit by writing '1'. Writing '0' has no effect.
Reserved bit, must be kept at reset value.
Doc ID 018909 Rev 4
RM0090