AN910 datasheet(32/51 Pages) STMICROELECTRONICS

32 / 51 page

32/51

ST7 AND ST9 PERFORMANCE BENCHMARKING

7.3.5 ST9 MCU core

On-chip/Off-chip buses

- on-chip buses

16-bit address bus

8/16-bit data/program memory bus

8-bit register bus

- off-chip buses

8/16-bit address bus

8-bit multiplexed data/program memory bus

the two buses may be multiplexed

the two buses are multiplexed with ports

Cpu internal buses

16-bit address

8-bit data multiplexed bus

Instruction set

Cisc encoding

- CPI

6 cycles to 38 cycles

- average CPI

between 16 and 18 cycles

- IL

1 byte to 6 bytes

- average IL

between 3 and 4 bytes

- special addressing modes

bit access to whole register file

indirect with pre/post-increment

indexed (short, long, register, memory)

- special instructions

exchange register contents

bit test & set

decrement & branch like

memory-to-memory moves

Instruction processing

Prefetch mechanism

- next byte prefetching

as soon as instruction register is available

and address is known

Arithmetic Logic Unit

8-bit datapath

- 8/16-bit operations

- special functions

8x8 unsigned multiplication

22 cycles

16/8 unsigned divisions

28/20 cycles

32/16 stepped unsigned divisions 28 cycles

+ / x

Programming model

- general purpose registers

14 groups of sixteen 8-bit registers

- system registers

one group of sixteen 8-bit registers

flags, central interrupt control register

user/system stack pointers

mode register, page pointer

2 register group pointers

i/o port data registers

- paged registers

on-chip peripheral data and control registers

up to 64 pages of sixteen 8-bit registers

- 16-bit program counter

- multitasking capabilities

context switching with register group pointers

ST9 CPU

LDW RRd,rrs

ADD Rd,#2

Memory Spaces

Harvard organization

- register file space

224 bytes of general purpose registers

system, on-chip peripheral, and i/o port registers

- linear data/program memory space

data memory space

up 64 kbytes

program memory space

up to 64 kbytes

first 256-byte interrupt vector table = 128 interrupts

AN910 数据表(PDF) 32 Page - STMicroelectronics

AN910 数据表(HTML) 32 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

数据表下载