參數(shù)資料
型號: pic12ce674
廠商: Microchip Technology Inc.
英文描述: 8-Pin, 8-Bit CMOS Microcontroller with A/D Converter(具A/D轉(zhuǎn)換器和EEPROM數(shù)據(jù)存儲器的8位微控制器)
中文描述: 8引腳,8位CMOS微控制器與A / D轉(zhuǎn)換器(具的A / D轉(zhuǎn)換器和EEPROM的數(shù)據(jù)存儲器的8位微控制器)
文件頁數(shù): 30/112頁
文件大?。?/td> 1205K
代理商: PIC12CE674
PIC12CE67X
DS40181A-page 30
Preliminary
1998 Microchip Technology Inc.
6.5
READ OPERATIONS
Read operations are initiated in the same way as write
operations with the exception that the R/W bit of the
EEPROM address is set to one. There are three basic
types of read operations: current address read, random
read, and sequential read.
6.5.1
CURRENT ADDRESS READ
It contains an address counter that maintains the
address of the last word accessed, internally incre-
mented by one. Therefore, if the previous read access
was to address n, the next current address read oper-
ation would access data from address n + 1. Upon
receipt of the EEPROM address with the R/W bit set to
one, the EEPROM issues an acknowledge and trans-
mits the eight bit data word. The processor will not
acknowledge the transfer but does generate a stop
condition and the EEPROM discontinues transmission
(Figure 6-6).
6.5.2
RANDOM READ
Random read operations allow the processor to access
any memory location in a random manner. To perform
this type of read operation, first the word address must
be set. This is done by sending the word address to the
EEPROM as part of a write operation. After the word
address is sent, the processor generates a start condi-
tion following the acknowledge. This terminates the
write operation, but not before the internal address
pointer is set. Then the processor issues the control
byte again but with the R/W bit set to a one. It will then
issue an acknowledge and transmits the eight bit data
word. The processor will not acknowledge the transfer
but does generate a stop condition and the EEPROM
discontinues transmission (Figure 6-7). After this com-
mand, the internal address counter will point to the
address location following the one that was just read.
6.5.3
SEQUENTIAL READ
Sequential reads are initiated in the same way as a ran-
dom read except that after the device transmits the first
data byte, the processor issues an acknowledge as
opposed to a stop condition in a random read. This
directs the EEPROM to transmit the next sequentially
addressed 8-bit word (Figure 6-8).
To provide sequential reads, it contains an internal
address pointer which is incremented by one at the
completion of each read operation. This address
pointer allows the entire memory contents to be serially
read during one operation.
FIGURE 6-6:
CURRENT ADDRESS READ
FIGURE 6-7:
RANDOM READ
FIGURE 6-8:
SEQUENTIAL READ
BUS ACTIVITY
PROCESSOR
SDA LINE
BUS ACTIVITY
P
S
S
T
O
P
CONTROL
BYTE
S
T
A
R
T
DATA
A
C
K
N
O
A
C
K
1
1
0
0 X X X 1
X = Don’t Care Bit
P
BUS ACTIVITY
PROCESSOR
SDA LINE
BUS ACTIVITY
S
T
A
R
T
S
T
O
P
CONTROL
BYTE
A
C
K
WORD
ADDRESS (n)
CONTROL
BYTE
S
T
A
R
T
DATA (n)
A
C
K
A
C
K
N
O
A
C
K
X X X X
S 1
1
0
0 X X X 0
S 1
1
0
0 X X X 1
X = Don’t Care Bit
P
BUS ACTIVITY
PROCESSOR
SDA LINE
BUS ACTIVITY
S
T
O
P
CONTROL
BYTE
A
C
K
N
O
C
K
DATA n
DATA n + 1
DATA n + 2
DATA n + X
A
C
K
A
C
K
A
C
K
相關(guān)PDF資料
PDF描述
PIC12CR509A 8-Pin, 8-Bit CMOS Microcontrollers
PIC12F505 8/14-Pin, 8-Bit Flash Microcontrollers
PIC12F506 8/14-Pin, 8-Bit Flash Microcontroller
PIC12F510_07 8/14-Pin, 8-Bit Flash Microcontroller
PIC12F510 8/14-Pin, 8-Bit Flash Microcontroller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC12CE674/JW 功能描述:8位微控制器 -MCU 3.5KB 128 RAM 6 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(fēng)格:SMD/SMT
PIC12CE674-04/JM 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontroller with A/D Converter
PIC12CE674-04/JW 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:8-Pin, 8-Bit CMOS Microcontroller with A/D Converter and EEPROM Data Memory
PIC12CE674-04/P 功能描述:8位微控制器 -MCU 3.5KB 128 RAM 6 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(fēng)格:SMD/SMT
PIC12CE674-04/P 制造商:Microchip Technology Inc 功能描述:IC 8BIT CMOS MCU 12CE674 DIP8