參數(shù)資料
型號: DTMFDECODER-RD
廠商: Silicon Laboratories Inc
文件頁數(shù): 173/178頁
文件大?。?/td> 0K
描述: KIT REF DESIGN DTMF DECODER
應(yīng)用說明: DTMF Decoder Ref Design AppNote
標(biāo)準(zhǔn)包裝: 1
主要目的: 電信,DTMF 解碼器
嵌入式:
已用 IC / 零件: C8051F300
主要屬性: 8kHz 采樣速率模數(shù)轉(zhuǎn)換器
次要屬性: 16 個(gè) Goertzel 濾波器
已供物品: 板,軟件
產(chǎn)品目錄頁面: 627 (CN2011-ZH PDF)
相關(guān)產(chǎn)品: 336-1535-5-ND - IC 8051 MCU 8K FLASH 14-SOIC
C8051F300-GMR-ND - IC 8051 MCU 8K FLASH 11QFN
336-1245-ND - IC 8051 MCU 8K FLASH 11QFN
其它名稱: 336-1283
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁當(dāng)前第173頁第174頁第175頁第176頁第177頁第178頁
C8051F300/1/2/3/4/5
94
Rev. 2.9
10.4. Flash Write and Erase Guidelines
Any system which contains routines which write or erase Flash memory from software involves some risk
that the write or erase routines will execute unintentionally if the CPU is operating outside its specified
operating range of VDD, system clock frequency, or temperature. This accidental execution of Flash modi-
fying code can result in alteration of Flash memory contents causing a system failure that is only recover-
able by re-Flashing the code in the device.
The following guidelines are recommended for any system which contains routines which write or erase
Flash from code.
10.4.1. VDD Maintenance and the VDD monitor
1.
If the system power supply is subject to voltage or current "spikes," add sufficient transient
protection devices to the power supply to ensure that the supply voltages listed in the Absolute
Maximum Ratings table are not exceeded.
2.
Make certain that the minimum VDD rise time specification of 1 ms is met. If the system cannot
meet this rise time specification, then add an external VDD brownout circuit to the RST pin of
the device that holds the device in reset until VDD reaches 2.7 V and re-asserts RST if VDD
drops below 2.7 V.
3.
Enable the on-chip VDD monitor and enable the VDD monitor as a reset source as early in code
as possible. This should be the first set of instructions executed after the Reset Vector. For 'C'-
based systems, this will involve modifying the startup code added by the 'C' compiler. See your
compiler documentation for more details. Make certain that there are no delays in software
between enabling the VDD monitor and enabling the VDD monitor as a reset source. Code
examples showing this can be found in “AN201: Writing to Flash from Firmware", available
from the Silicon Laboratories web site.
4.
As an added precaution, explicitly enable the VDD monitor and enable the VDD monitor as a
reset source inside the functions that write and erase Flash memory. The VDD monitor enable
instructions should be placed just after the instruction to set PSWE to a '1', but before the
Flash write or erase operation instruction.
5.
Make certain that all writes to the RSTSRC (Reset Sources) register use direct assignment
operators and explicitly DO NOT use the bit-wise operators (such as AND or OR). For exam-
ple, "RSTSRC = 0x02" is correct. "RSTSRC |= 0x02" is incorrect.
6.
Make certain that all writes to the RSTSRC register explicitly set the PORSF bit to a '1'. Areas
to check are initialization code which enables other reset sources, such as the Missing Clock
Detector or Comparator, for example, and instructions which force a Software Reset. A global
search on "RSTSRC" can quickly verify this.
10.4.2. PSWE Maintenance
7.
Reduce the number of places in code where the PSWE bit (b0 in PSCTL) is set to a '1'. There
should be exactly one routine in code that sets PSWE to a '1' to write Flash bytes and one rou-
tine in code that sets PSWE and PSEE both to a '1' to erase Flash pages.
8.
Minimize the number of variable accesses while PSWE is set to a '1'. Handle pointer address
updates and loop variable maintenance outside the "PSWE = 1; ... PSWE = 0;" area. Code
examples showing this can be found in AN201, "Writing to Flash from Firmware", available
from the Silicon Laboratories web site.
9.
Disable interrupts prior to setting PSWE to a '1' and leave them disabled until after PSWE has
been reset to '0'. Any interrupts posted during the Flash write or erase operation will be ser-
相關(guān)PDF資料
PDF描述
UPZ2E121MND9 CAP ALUM 120UF 250V 20% RADIAL
A3KKB-1036M IDC CABLE - APK10B/AE10M/APK10B
UVR2G101MRD6 CAP ALUM 100UF 400V 20% RADIAL
LLS2A102MELZ CAP ALUM 1000UF 100V 20% SNAP
SI5310-EVB BOARD EVALUATION FOR SI5310
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DTMG5812L WAF 制造商:ON Semiconductor 功能描述:
DTMG5852L WAF 制造商:ON Semiconductor 功能描述:
DTMH04-2PA 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE DTM HI TEMP A KEY 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, A KEY, 2WAY, Series:DTMH, No. of Positions:2, Gender:Receptacle, No. of Rows:1 , RoHS Compliant: Yes
DTMH04-2PB 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE DTM HI TEMP B KEY 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, B KEY, 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, B KEY, 2WAY; Series:DTMH; Gender:Receptacle; No. of Contacts:2; No. of Rows:1; Contact Gender:Pin; Connector Mounting:Cable; Connector Shell Size:-; Contact Termination:Crimp; Contact Material:Copper; Contact;RoHS Compliant: Yes
DTMH04-2PC 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE DTM HI TEMP C KEY 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, C KEY, 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, C KEY, 2WAY; Series:DTMH; Gender:Receptacle; No. of Contacts:2; No. of Rows:1; Contact Gender:Pin; Connector Mounting:Cable; Connector Shell Size:-; Contact Termination:Crimp; Contact Material:Copper; Contact;RoHS Compliant: Yes