參數(shù)資料
型號(hào)： PSD9345V12JT
廠商： 意法半導(dǎo)體
英文描述： Low Power Economy BiCMOS Current Mode PWM 8-SOIC -40 to 85
中文描述： Flash在系統(tǒng)可編程ISP的外設(shè)的8位微控制器
文件頁(yè)數(shù)： 25/110頁(yè)
文件大?。?/td> 1737K
代理商： PSD9345V12JT
25/110
PSD813F2, PSD833F2, PSD834F2, PSD853F2, PSD854F2
PROGRAMMING FLASH MEMORY
Flash memory must be erased prior to being pro-
grammed. A byte of Flash memory is erased to all
1s (FFh), and is programmed by setting selected
bits to ’0.’ The MCU may erase Flash memory all
at once or by-sector, but not byte-by-byte. Howev-
er, the MCU may program Flash memory byte-by-
byte.
The primary and secondary Flash memories re-
quire the MCU to send an instruction to program a
byte or to erase sectors (see
Table 9., page 21
).
Once the MCU issues a Flash memory Program or
Erase instruction, it must check for the status bits
for completion. The embedded algorithms that are
invoked inside the PSD support several means to
provide status to the MCU. Status may be checked
using any of three methods: Data Polling, Data
Toggle, or Ready/Busy (PC3).
Data Polling
Polling on the Data Polling Flag Bit (DQ7) is a
method of checking whether a Program or Erase
cycle is in progress or has completed. Figure
7
shows the Data Polling algorithm.
When the MCU issues a Program instruction, the
embedded algorithm within the PSD begins. The
MCU then reads the location of the byte to be pro-
grammed in Flash memory to check status. The
Data Polling Flag Bit (DQ7) of this location be-
comes the complement of b7 of the original data
byte to be programmed. The MCU continues to
poll this location, comparing the Data Polling Flag
Bit (DQ7) and monitoring the Error Flag Bit (DQ5).
When the Data Polling Flag Bit (DQ7) matches b7
of the original data, and the Error Flag Bit (DQ5)
remains ’0,’ the embedded algorithm is complete.
If the Error Flag Bit (DQ5) is '1,' the MCU should
test the Data Polling Flag Bit (DQ7) again since
the Data Polling Flag Bit (DQ7) may have changed
simultaneously with the Error Flag Bit (DQ5, see
Figure
7
).
The Error Flag Bit (DQ5) is set if either an internal
time-out occurred while the embedded algorithm
attempted to program the byte or if the MCU at-
tempted to program a '1' to a bit that was not
erased (not erased is logic '0').
It is suggested (as with all Flash memories) to read
the location again after the embedded program-
ming algorithm has completed, to compare the
byte that was written to the Flash memory with the
byte that was intended to be written.
When using the Data Polling method during an
Erase cycle, Figure
7
still applies. However, the
Data Polling Flag Bit (DQ7) is '0' until the Erase cy-
cle is complete. A 1 on the Error Flag Bit (DQ5) in-
dicates a time-out condition on the Erase cycle; a
0 indicates no error. The MCU can read any loca-
tion within the sector being erased to get the Data
Polling Flag Bit (DQ7) and the Error Flag Bit
(DQ5).
PSDsoft Express generates ANSI C code func-
tions which implement these Data Polling algo-
rithms.
Figure 7. Data Polling Flowchart
READ DQ5 & DQ7
at VALID ADDRESS
START
READ DQ7
FAIL
PASS
AI01369B
D=
DATA
YES
NO
YES
NO
DQ5
= 1
D=
DATA
YES
NO
相關(guān)PDF資料
PDF描述
PSD9345V12MIT Flash In-System Programmable ISP Peripherals For 8-bit MCUs
PSD9345V12MT Low Power Economy BiCMOS Current Mode PWM 8-SOIC -40 to 85
PSD9345V15JIT Flash In-System Programmable ISP Peripherals For 8-bit MCUs
PSD9345V15JT Low Power Economy BiCMOS Current Mode PWM 8-PDIP -40 to 85
PSD9345V15MIT Flash In-System Programmable ISP Peripherals For 8-bit MCUs
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PSD934F2-15J 功能描述:SPLD - 簡(jiǎn)單可編程邏輯器件 5V 2M 150ns RoHS:否 制造商:Texas Instruments 邏輯系列:TICPAL22V10Z 大電池?cái)?shù)量:10 最大工作頻率:66 MHz 延遲時(shí)間:25 ns 工作電源電壓:4.75 V to 5.25 V 電源電流:100 uA 最大工作溫度:+ 75 C 最小工作溫度:0 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:DIP-24
PSD934F290J 制造商:WSI 功能描述:
PSD934F2-90J 功能描述:SPLD - 簡(jiǎn)單可編程邏輯器件 PLCC-52 5V 2M 90NS RoHS:否 制造商:Texas Instruments 邏輯系列:TICPAL22V10Z 大電池?cái)?shù)量:10 最大工作頻率:66 MHz 延遲時(shí)間:25 ns 工作電源電壓:4.75 V to 5.25 V 電源電流:100 uA 最大工作溫度:+ 75 C 最小工作溫度:0 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:DIP-24
PSD934F2-90M 功能描述:SPLD - 簡(jiǎn)單可編程邏輯器件 5V 2M 90ns RoHS:否 制造商:Texas Instruments 邏輯系列:TICPAL22V10Z 大電池?cái)?shù)量:10 最大工作頻率:66 MHz 延遲時(shí)間:25 ns 工作電源電壓:4.75 V to 5.25 V 電源電流:100 uA 最大工作溫度:+ 75 C 最小工作溫度:0 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:DIP-24
PSD934F2V-15J 功能描述:SPLD - 簡(jiǎn)單可編程邏輯器件 3.3V 2M 150ns RoHS:否 制造商:Texas Instruments 邏輯系列:TICPAL22V10Z 大電池?cái)?shù)量:10 最大工作頻率:66 MHz 延遲時(shí)間:25 ns 工作電源電壓:4.75 V to 5.25 V 電源電流:100 uA 最大工作溫度:+ 75 C 最小工作溫度:0 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:DIP-24
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