参数资料
型号: ST72511R6T1/XXX
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP64
封装: 14 X 14 MM, TQFP-64
文件页数: 74/164页
文件大小: 1043K
代理商: ST72511R6T1/XXX
ST72311R, ST72511R, ST72512R, ST72532R
17/164
DATA EEPROM (Cont’d)
3.3 MEMORY ACCESS
The Data EEPROM memory read/write access
modes are controlled by the LAT bit of the EEP-
ROM Control/Status register (EECSR). The flow-
chart in Figure 5 describes these different memory
access modes.
Read Operation (LAT=0)
The EEPROM can be read as a normal ROM loca-
tion when the LAT bit of the EECSR register is
cleared. In a read cycle, the byte to be accessed is
put on the data bus in less than 1 CPU clock cycle.
This means that reading data from EEPROM
takes the same time as reading data from
EPROM, but this memory cannot be used to exe-
cute machine code.
Write Operation (LAT=1)
To access the write mode, the LAT bit has to be
set by software (the PGM bit remains cleared).
When a write access to the EEPROM area occurs,
the value is latched inside the 16 data latches ac-
cording to its address.
When PGM bit is set by the software, all the previ-
ous bytes written in the data latches (up to 16) are
programmed in the EEPROM cells. The effective
high address (row) is determined by the last EEP-
ROM write sequence. To avoid wrong program-
ming, the user must take care that all the bytes
written between two programming sequences
have the same high address: only the four Least
Significant Bits of the address can change.
At the end of the programming cycle, the PGM and
LAT bits are cleared simultaneously, and an inter-
rupt is generated if the IE bit is set. The Data EEP-
ROM interrupt request is cleared by hardware
when the Data EEPROM interrupt vector is
fetched.
Note: Care should be taken during the program-
ming cycle. Writing to the same memory location
will over-program the memory (logical AND be-
tween the two write access data result) because
the data latches are only cleared at the end of the
programming cycle and by the falling edge of LAT
bit.
It is not possible to read the latched data.
This note is ilustrated by the Figure 6.
Figure 5. Data EEPROM Programming Flowchart
READ MODE
LAT=0
PGM=0
WRITE MODE
LAT=1
PGM=0
READ BYTES
IN EEPROM AREA
WRITE UP TO 16 BYTES
IN EEPROM AREA
(with the same 12 MSB of the address)
START PROGRAMMING CYCLE
LAT=1
PGM=1 (set by software)
LAT
INTERRUPT GENERATION
IF IE=1
0
1
CLEARED BY HARDWARE
相关PDF资料
PDF描述
ST72T511R7T1 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PQFP64
ST72T631L4M1 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDSO34
SAB80C537-M 8-BIT, 12 MHz, MICROCONTROLLER, PQFP100
SAF-C504-2R40M 8-BIT, MROM, 40 MHz, MICROCONTROLLER, PQFP44
SAB-C517A-4R24M 8-BIT, MROM, 24 MHz, MICROCONTROLLER, PQFP100
相关代理商/技术参数
参数描述
ST72561K4 制造商:STMicroelectronics 功能描述:LOW SPEED USB 8-BIT MCU WITH 3 ENDPOINTS,FLASH MEMORY, - Bulk
ST72589-EMU2 功能描述:仿真器/模拟器 ST7 Emulator Board RoHS:否 制造商:Blackhawk 产品:System Trace Emulators 工具用于评估:C6000, C5000, C2000, OMAP, DAVINCI, SITARA, TMS470, TMS570, ARM 7/9, ARM Cortex A8/R4/M3 用于:XDS560v2
ST72611F1 制造商:STMicroelectronics 功能描述:LOW SPEED USB 8-BIT MCU WITH 3 ENDPOINTS,FLASH MEMORY, - Bulk
ST7263-EMU2 功能描述:仿真器/模拟器 ST7 Emulator Board RoHS:否 制造商:Blackhawk 产品:System Trace Emulators 工具用于评估:C6000, C5000, C2000, OMAP, DAVINCI, SITARA, TMS470, TMS570, ARM 7/9, ARM Cortex A8/R4/M3 用于:XDS560v2
ST7265X-EVAL/MS 制造商:STMicroelectronics 功能描述:ST6 EVAL BD - Bulk