- 您現在的位置：買賣IC網 > PDF目錄363901 > W79E648 (WINBOND ELECTRONICS CORP) Fast 8051 Compatible microcontroller with a redesigned Processor PDF資料下載
參數資料
| 型號： | W79E648 |
| 廠商： | WINBOND ELECTRONICS CORP |
| 英文描述： | Fast 8051 Compatible microcontroller with a redesigned Processor |
| 中文描述： | 快速8051兼容微控制器重新設計的處理器 |
| 文件頁數： | 31/80頁 |
| 文件大小： | 407K |
| 代理商： | W79E648 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁當前第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁
Preliminary W79E648
Publication Release Date: 05/31/2004
- 31 - Revision A1
OPERAND
OPERAND
OPERAND
OP-CODE
Address A15-8
Address A15-8
Address A15-8
Address A15-8
A7-0
A7-0
A7-0
A7-0
Operand Fetch
Operand Fetch
Operand Fetch
Operand Fetch
Instruction Fetch
C2
C1
C4
C3
C2
C1
CLK
ALE
PSEN
AD7-0
PORT 2
C4
C3
C2
C1
C4
C3
C2
C1
C4
C3
C2
C1
C4
C3
OPERAND
A7-0
Address A15-8
Figure 7. Five Cycle Instruction Timing
7.1.1 External Data Memory Access Timing
The timing for the MOVX instruction is another feature of the W79E648. In the standard 8032, the
MOVX instruction has a fixed execution time of 2 machine cycles. However in the W79E648, the
duration of the access can be varied by the user.
The instruction starts off as a normal op-code fetch of 4 clocks. In the next machine cycle, the
W79E648 puts out the address of the external Data Memory and the actual access occurs here. The
user can change the duration of this access time by setting the STRETCH value. The Clock Control
SFR (CKCON) has three bits that control the stretch value. These three bits are M2-0 (bits 2-0 of
CKCON). These three bits give the user 8 different access time options. The stretch can be varied
from 0 to 7, resulting in MOVX instructions that last from 2 to 9 machine cycles in length. Note that the
stretching of the instruction only results in the elongation of the MOVX instruction, as if the state of the
CPU was held for the desired period. There is no effect on any other instruction or its timing. By
default, the Stretch value is set at 1, giving a MOVX instruction of 3 machine cycles. If desired by the
user the stretch value can be set to 0 to give the fastest MOVX instruction of only 2 machine cycles.
Table 4. Data Memory Cycle Stretch Values
M2
M1
M0
Machine
Cycles
RD
or
WR
strobe width
in Clocks
2
4
8
RD
or
WR
strobe width
@ 25 MHz
80 nS
160 nS
320 nS
RD
or
WR
strobe width
@ 40 MHz
50 nS
100 nS
200 nS
0
0
0
0
0
1
0
1
0
2
3 (default)
4
相關PDF資料 |
PDF描述 |
|---|---|
| W79E802 | 8-BIT MICROCONTROLLER |
| W79E802A | 8-BIT MICROCONTROLLER |
| W79E802ADG | 8-BIT MICROCONTROLLER |
| W79E802ASG | 8-BIT MICROCONTROLLER |
| W79E803 | 8-BIT MICROCONTROLLER |
相關代理商/技術參數 |
參數描述 |
|---|---|
| W79E658A40FL | 制造商:Nuvoton Technology Corp 功能描述:IC MCU 8BIT 100QFP |
| W79E659A40FL | 制造商:Nuvoton Technology Corp 功能描述:IC MCU 8BIT 100QFP |
| W79E802 | 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT MICROCONTROLLER |
| W79E802A | 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT MICROCONTROLLER |
| W79E802ADG | 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT MICROCONTROLLER |
發布緊急采購，3分鐘左右您將得到回復。