ST20CX datasheet(11/212 Pages) STMICROELECTRONICS

11 / 212 page

11/212

1.7.6

On-chip peripherals

On-chip peripherals may have memory-mapped registers in the address range

PeripheralStart to PeripheralEnd. Access to these registers is represented in the

following way:

PeripheralByte[

address] references an 8-bit peripheral register

PeripheralSixteen[

address] references a 16-bit peripheral register

PeripheralWord[

address] references a 32-bit peripheral register

For all of these, the state of the peripheral referenced is that

before the instruction if

the function is used without a prime (e.g. PeripheralWord[]), and that

after the

instruction if the function is used with a prime (e.g. PeripheralWord

′[]).

For example, writing a value given by an expression,

expr, to the register at address

addr is represented by:

PeripheralWord

′[addr] ← expr

and reading a word from a peripheral is achieved by:

Areg

′← PeripheralWord[addr]

1.8

Block move registers

A group of registers is used in the implementation of block moves. These are referred

to as the ‘block move registers’ and include

Move2dBlockLength, Move2dDestStride,

and

Move2dSourceStride.

1.9

Constants

A number of data structures have been defined in this book. Each compr ises a

number of data slots that are referenced by name in the text and the following

instructions descriptions.

These data structures is listed in Table 1.2 to Table 1.4.

word offset

slot name

purpose

pw.Temp

slot used by some instructions for storing temporary values

-1

pw.Iptr

the instruction pointer of a descheduled process

-2

pw.Link

the address of the workspace of the next process in scheduling list

-3

pw.Pointer

saved pointer to communication data area

-3

pw.State

saved alternative state

-4

pw.TLink

address of the workspace of the next process on the timer list

-5

pw.Time

time that a process on a timer list is waiting for

Table 1.1 Process workspace data structure

ST20CX Datasheet(PDF) 11 Page - STMicroelectronics

ST20CX Datasheet(HTML) 11 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL