Holtek HT66F30 - Page 239

Rev. 2.50 238 June 22, 2017 Rev. 2.50 239 June 22, 2017
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
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
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
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 














 
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MCU to UART Internal Connection
Note:PCKoutputfrequencymustbe≤12MHz.
UART Module SPI Interface
TheMCUcommunicateswiththeUARTModuleviaaninternalSPIinterface.TheSPIinterfaceon
thisdeviceiscomprisedoffoursignals:SCS(SPIChipSelect),SCK(SPIClock),SDI(SerialData
Input)andSDO(SerialDataOutput).TheSPImaster,whichistheMCU,assertsSCSbypullingit
lowtostartthedatatransactioncycle.Whentherst8bitsofdataaretransmitted,SCSshouldnot
returntoahighlevel.Instead,SCSmustremainatalowleveluntilthewhole16-bitdatatransaction
iscompleted.IfSCSisde-asserted,thatisreturnedtoahighlevelbeforethe16-bitdatatransaction
iscompleted,alldatabitswillbediscardedbytheUARTModuleSPIslave.
SPI Timing
BothreadandwriteoperationsareconductedalongtheSPIcommoninterfacewiththefollowing
format:
•
WriteTypeFormat:8-bitcommandinput+8-bitdatainput
• ReadTypeFormat:8-bitcommandinput+8-bitdataoutput
SDO
SDI
SCK
SCS
A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
Writing Type Format: 8-bit Command Input + 8-bit Data Input
SDO
SDI
SCK
SCS
A7 A6 A5 A4 A3 A2 A1 A0
D7 D6 D5 D4 D3 D2 D1 D0
t
w
Reading Type Format: 8-bit Command Input + 8-bit Data Output