Holtek HT66F20 - Page 187

Rev. 2.50 186 June 22, 2017 Rev. 2.50 187 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
SPI Registers
TherearethreeinternalregisterswhichcontroltheoveralloperationoftheSPIinterface.Theseare
theSIMDdataregisterandtworegistersSIMC0andSIMC2.NotethattheSIMC1registerisonly
usedbytheI
2
Cinterface.
Register
Name
Bit
7 6 5 4 3 2 1 0
SIMC0 SIM2
SIM1 SIM0 PCKEN PCKP1 PCKP0 SIMEN —
SIMD
D7 D6 D5 D4 D3 D2 D1 D0
SIMC2
D7 D6 CKPOLB CKEG MLS CSEN WCOL TRF
SIM Registers List
TheSIMDregisterisusedtostorethedatabeingtransmittedandreceived.Thesameregisterisused
byboththeSPIandI
2
Cfunctions.BeforethedevicewritesdatatotheSPIbus,theactualdatato
betransmittedmustbeplacedintheSIMDregister.AfterthedataisreceivedfromtheSPIbus,the
devicecanreaditfromtheSIMDregister.AnytransmissionorreceptionofdatafromtheSPIbus
mustbemadeviatheSIMDregister.
• SIMD Register
Bit 7 6 5 4 3 2 1 0
Name
D7 D6 D5 D4 D3 D2 D1 D0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
POR × × × × × × × ×
“x”: unknown
TherearealsotwocontrolregistersfortheSPIinterface,SIMC0andSIMC2.NotethattheSIMC2
registeralsohasthenameSIMAwhichisusedbytheI
2
Cfunction.TheSIMC1registerisnotused
bytheSPIfunction,onlybytheI
2
Cfunction.RegisterSIMC0isusedtocontroltheenable/disable
functionandtosetthedatatransmissionclockfrequency.AlthoughnotconnectedwiththeSPI
function,theSIMC0registerisalsousedtocontrolthePeripheralClockPrescaler.RegisterSIMC2
isusedforothercontrolfunctionssuchasLSB/MSBselection,writecollisionagetc.