參數(shù)資料
型號: PIC18LF6620-I/PT
廠商: Microchip Technology
文件頁數(shù): 149/165頁
文件大小: 0K
描述: IC MCU FLSH 1MBIT W/AD LP 64TQFP
產品培訓模塊: Asynchronous Stimulus
標準包裝: 160
系列: PIC® 18F
核心處理器: PIC
芯體尺寸: 8-位
速度: 25MHz
連通性: I²C,SPI,UART/USART
外圍設備: 欠壓檢測/復位,LVD,POR,PWM,WDT
輸入/輸出數(shù): 52
程序存儲器容量: 64KB(32K x 16)
程序存儲器類型: 閃存
EEPROM 大?。?/td> 1K x 8
RAM 容量: 3.75K x 8
電壓 - 電源 (Vcc/Vdd): 2 V ~ 5.5 V
數(shù)據(jù)轉換器: A/D 12x10b
振蕩器型: 外部
工作溫度: -40°C ~ 85°C
封裝/外殼: 64-TQFP
包裝: 托盤
PIC18F6520/8520/6620/8620/6720/8720
DS39609B-page 82
2004 Microchip Technology Inc.
7.5
Write Verify
Depending on the application, good programming
practice may dictate that the value written to the mem-
ory should be verified against the original value. This
should be used in applications where excessive writes
can stress bits near the specification limit.
7.6
Protection Against Spurious Write
There are conditions when the user may not want to
write to the data EEPROM memory. To protect against
spurious EEPROM writes, various mechanisms have
been built-in. On power-up, the WREN bit is cleared.
Also, the Power-up Timer (72 ms duration) prevents
EEPROM write.
The write initiate sequence and the WREN bit together
help prevent an accidental write during brown-out,
power glitch, or software malfunction.
7.7
Operation During Code-Protect
Data EEPROM memory has its own code-protect
mechanism. External read and write operations are
disabled if either of these mechanisms are enabled.
The microcontroller itself can both read and write to the
internal data EEPROM, regardless of the state of the
code-protect configuration bit. Refer to Section 23.0
information.
7.8
Using the Data EEPROM
The data EEPROM is a high endurance, byte address-
able array that has been optimized for the storage of
frequently changing information (e.g., program vari-
ables or other data that are updated often). Frequently
changing values will typically be updated more often
than specification D124. If this is not the case, an array
refresh must be performed. For this reason, variables
that change infrequently (such as constants, IDs,
calibration, etc.) should be stored in Flash program
memory.
A simple data EEPROM refresh routine is shown in
EXAMPLE 7-3:
DATA EEPROM REFRESH ROUTINE
Note:
If data EEPROM is only used to store
constants and/or data that changes rarely,
an array refresh is likely not required. See
specification D124.
CLRF
EEADR
; Start at address 0
CLRF
EEADRH
;
BCF
EECON1, CFGS
; Set for memory
BCF
EECON1, EEPGD
; Set for Data EEPROM
BCF
INTCON, GIE
; Disable interrupts
BSF
EECON1, WREN
; Enable writes
Loop
; Loop to refresh array
BSF
EECON1, RD
; Read current address
MOVLW
55h
;
MOVWF
EECON2
; Write 55h
MOVLW
AAh
;
MOVWF
EECON2
; Write AAh
BSF
EECON1, WR
; Set WR bit to begin write
BTFSC
EECON1, WR
; Wait for write to complete
BRA
$-2
INCFSZ
EEADR, F
; Increment address
BRA
Loop
; Not zero, do it again
INCFSZ
EEADRH, F
; Increment the high address
BRA
Loop
; Not zero, do it again
BCF
EECON1, WREN
; Disable writes
BSF
INTCON, GIE
; Enable interrupts
相關PDF資料
PDF描述
65175-002LF BP COVER LF
PIC18F8628-I/PT IC PIC MCU FLASH 48KX16 80TQFP
PIC17C756A-16I/L IC MCU OTP 16KX16 A/D PWM 68PLCC
PIC17C44-33/P IC MCU OTP 8KX16 PWM 40DIP
PIC18LF6628-I/PT IC PIC MCU FLASH 48KX16 64TQFP
相關代理商/技術參數(shù)
參數(shù)描述
PIC18LF6620T-I/PT 功能描述:8位微控制器 -MCU 64KB 3840 RAM 52I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18LF6621-I/PT 功能描述:8位微控制器 -MCU 64KB 3840 RAM 52I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18LF6621-I/PTG 功能描述:8位微控制器 -MCU 64kBF 3840RM 52 I/O Lead Free Package RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18LF6621T-I/PT 功能描述:8位微控制器 -MCU 64KB 3840 RAM 52I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC18LF6622-I/PT 功能描述:8位微控制器 -MCU 64 KB FL 4K RAM 70 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT