參數(shù)資料
型號(hào): PIC18F2321T-I/SS
廠商: Microchip Technology
文件頁數(shù): 102/110頁
文件大?。?/td> 0K
描述: IC PIC MCU FLASH 4KX16 28SSOP
標(biāo)準(zhǔn)包裝: 2,100
系列: PIC® 18F
核心處理器: PIC
芯體尺寸: 8-位
速度: 40MHz
連通性: I²C,SPI,UART/USART
外圍設(shè)備: 欠壓檢測/復(fù)位,HLVD,POR,PWM,WDT
輸入/輸出數(shù): 25
程序存儲(chǔ)器容量: 8KB(4K x 16)
程序存儲(chǔ)器類型: 閃存
EEPROM 大小: 256 x 8
RAM 容量: 512 x 8
電壓 - 電源 (Vcc/Vdd): 4.2 V ~ 5.5 V
數(shù)據(jù)轉(zhuǎn)換器: A/D 10x10b
振蕩器型: 內(nèi)部
工作溫度: -40°C ~ 85°C
封裝/外殼: 28-SSOP(0.209",5.30mm 寬)
包裝: 帶卷 (TR)
2009 Microchip Technology Inc.
DS39689F-page 91
PIC18F2221/2321/4221/4321 FAMILY
8.2
Reading the Data EEPROM
Memory
To read a data memory location, the user must write the
address to the EEADR register, clear the EEPGD
control bit (EECON1<7>) and then set control bit, RD
(EECON1<0>). The data is available on the very next
instruction cycle; therefore, the EEDATA register can
be read by the next instruction. EEDATA will hold this
value until another read operation, or until it is written to
by the user (during a write operation).
The basic process is shown in Example 8-1.
8.3
Writing to the Data EEPROM
Memory
To write an EEPROM data location, the address must
first be written to the EEADR register and the data
written to the EEDATA register. The sequence in
Example 8-2 must be followed to initiate the write cycle.
The write will not begin if this sequence is not exactly
followed (write 55h to EECON2, write 0AAh to
EECON2, then set WR bit) for each byte. It is strongly
recommended that interrupts be disabled during this
code segment.
Additionally, the WREN bit in EECON1 must be set to
enable writes. This mechanism prevents accidental
writes to data EEPROM due to unexpected code
execution (i.e., runaway programs). The WREN bit
should be kept clear at all times, except when updating
the EEPROM. The WREN bit is not cleared by
hardware.
After a write sequence has been initiated, EECON1,
EEADR and EEDATA cannot be modified. The WR bit
will be inhibited from being set unless the WREN bit is
set. The WREN bit must be set on a previous instruc-
tion. Both WR and WREN cannot be set with the same
instruction.
At the completion of the write cycle, the WR bit is
cleared in hardware and the EEPROM Interrupt Flag
bit, EEIF, is set. The user may either enable this
interrupt, or poll this bit. EEIF must be cleared by
software.
8.4
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.
EXAMPLE 8-1:
DATA EEPROM READ
EXAMPLE 8-2:
DATA EEPROM WRITE
MOVLW
DATA_EE_ADDR
;
MOVWF
EEADR
; Data Memory Address to read
BCF
EECON1, EEPGD
; Point to DATA memory
BCF
EECON1, CFGS
; Access EEPROM
BSF
EECON1, RD
; EEPROM Read
MOVF
EEDATA, W
; W = EEDATA
MOVLW
DATA_EE_ADDR
;
MOVWF
EEADR
; Data Memory Address to write
MOVLW
DATA_EE_DATA
;
MOVWF
EEDATA
; Data Memory Value to write
BCF
EECON1, EEPGD
; Point to DATA memory
BCF
EECON1, CFGS
; Access EEPROM
BSF
EECON1, WREN
; Enable writes
BCF
INTCON, GIE
; Disable Interrupts
MOVLW
55h
;
Required
MOVWF
EECON2
; Write 55h
Sequence
MOVLW
0AAh
;
MOVWF
EECON2
; Write 0AAh
BSF
EECON1, WR
; Set WR bit to begin write
BTFSC
EECON1, WR
; Wait for write to complete
GOTO
$-2
BSF
INTCON, GIE
; Enable Interrupts
; User code execution
BCF
EECON1, WREN
; Disable writes on write complete (EEIF set)
相關(guān)PDF資料
PDF描述
PIC18F2221T-I/SS IC PIC MCU FLASH 2KX16 28SSOP
PIC18F4682T-I/ML IC PIC MCU FLASH 40KX16 44QFN
PIC24HJ128GP306T-I/PT IC PIC MCU FLASH 128KB 64TQFP
PIC24FJ96GA008T-I/PT IC PIC MCU FLASH 96KB 80TQFP
PIC24FJ64GA010T-I/PT IC PIC MCU FLASH 64KB 100TQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC18F2331-E/ML 功能描述:8位微控制器 -MCU 8KB 768 RAM 22 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT
PIC18F2331-E/MM 功能描述:8位微控制器 -MCU 8KB 768 RAM 22 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT
PIC18F2331-E/SO 功能描述:8位微控制器 -MCU 8KB 768 RAM 22 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT
PIC18F2331-E/SP 功能描述:8位微控制器 -MCU 8KB 768 RAM 22 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT
PIC18F2331-I/ML 功能描述:8位微控制器 -MCU 8KB 768 RAM 22 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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(fēng)格:SMD/SMT