參數(shù)資料
型號(hào): MR80C32E-20
廠商: ATMEL CORP
元件分類(lèi): 微控制器/微處理器
英文描述: 8-BIT, 20 MHz, MICROCONTROLLER, CQCC44
封裝: LCC-44
文件頁(yè)數(shù): 15/32頁(yè)
文件大?。?/td> 3152K
代理商: MR80C32E-20
21
7707F–AVR–11/10
AT90USB82/162
4.
Write new EEPROM data to EEDR (optional).
5.
Write a logical one to the EEMPE bit while writing a zero to EEPE in EECR.
6.
Within four clock cycles after setting EEMPE, write a logical one to EEPE.
The EEPROM can not be programmed during a CPU write to the Flash memory. The software
must check that the Flash programming is completed before initiating a new EEPROM write.
Step 2 is only relevant if the software contains a Boot Loader allowing the CPU to program the
Flash. If the Flash is never being updated by the CPU, step 2 can be omitted. See “Memory Pro-
gramming” on page 243 for details about Boot programming.
Caution: An interrupt between step 5 and step 6 will make the write cycle fail, since the
EEPROM Master Write Enable will time-out. If an interrupt routine accessing the EEPROM is
interrupting another EEPROM access, the EEAR or EEDR Register will be modified, causing the
interrupted EEPROM access to fail. It is recommended to have the Global Interrupt Flag cleared
during all the steps to avoid these problems.
When the write access time has elapsed, the EEPE bit is cleared by hardware. The user soft-
ware can poll this bit and wait for a zero before writing the next byte. When EEPE has been set,
the CPU is halted for two cycles before the next instruction is executed.
Bit 0 – EERE: EEPROM Read Enable
The EEPROM Read Enable Signal EERE is the read strobe to the EEPROM. When the correct
address is set up in the EEAR Register, the EERE bit must be written to a logic one to trigger the
EEPROM read. The EEPROM read access takes one instruction, and the requested data is
available immediately. When the EEPROM is read, the CPU is halted for four cycles before the
next instruction is executed.
The user should poll the EEPE bit before starting the read operation. If a write operation is in
progress, it is neither possible to read the EEPROM, nor to change the EEAR Register.
The calibrated Oscillator is used to time the EEPROM accesses. Table 5-2 lists the typical pro-
gramming time for EEPROM access from the CPU.
The following code examples show one assembly and one C function for writing to the
EEPROM. The examples assume that interrupts are controlled (e.g. by disabling interrupts glob-
ally) so that no interrupts will occur during execution of these functions. The examples also
Table 5-2.
EEPROM Programming Time
Symbol
Number of Calibrated RC Oscillator Cycles
Typ Programming Time
EEPROM write
(from CPU)
26,368
3.3 ms
相關(guān)PDF資料
PDF描述
MV80C51T-20D 8-BIT, MROM, 20 MHz, MICROCONTROLLER, PQFP44
MT80C51C-36D 8-BIT, MROM, 36 MHz, MICROCONTROLLER, PQFP44
MD80C32E-16SCD 8-BIT, 16 MHz, MICROCONTROLLER, CDIP40
MD80C52CXXX-16P883D 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CDIP40
MD80C32-20SC 8-BIT, 20 MHz, MICROCONTROLLER, CDIP40
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MR80C51BH 制造商:ROCHESTER 制造商全稱(chēng):ROCHESTER 功能描述:CMOS SINGLE - CHIP 8-BIT MICROCOMPUTER 64K program Memory Space
MR80C86 制造商:INTERSIL 制造商全稱(chēng):Intersil Corporation 功能描述:CMOS 16-Bit Microprocessor
MR80C86/B 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Harris Corporation 功能描述:Microprocessor, 16 Bit, 44 Pin, Ceramic, LCC
MR80C86-2 制造商:INTERSIL 制造商全稱(chēng):Intersil Corporation 功能描述:CMOS 16-Bit Microprocessor
MR80C86-2/883 制造商:Rochester Electronics LLC 功能描述:- Bulk