1. Introduction of Holtek HT-46 series MCU

2. Content Family of A/D Type MCU 1. Cost-Effective A/D type MCU
3. A/D with LCD type MCU
4. A/D with VFD type MCU
5. A/D with OPA type MCU
Detail of HT46R24
1. Features of HT46R24
2. Block Diagram
3. Function Description(ROM, RAM, Interrupt, I/O, Timer, Buzzer, Oscillator, ADC, I2C, PWM, ….)

3. Cost-Effective A/D Type MCU

4. A/D Type MCU

5. Features of HT46R24

6. Block Diagram

7. HT46X24 Pin Assignment

8. Program ROM and Interrupt Vector

9. RAM MAPPING

10. 63 Instructions Arithmetic Increment & Decrement Logic Operation
ADD, SUB…
Increment & Decrement
INC, INCA, DEC…
Logic Operation
AND, OR, XOR…
Rotate
RR, RRC, RL…
Data Move
MOV…
Bit operation
SET, CLR…
Table Read
TABRDC, TABRDL
Branch
JMP, SZ, RET, RETI…
Miscellaneous
NOP, SWAP, HALT…

11. Arithmetic

12. Logic, Increment, Decrement

13. Rotate, Data Move, Bit Operation

14. Branch

15. Table Read ,Miscellaneous

16. Indirect Addressing Indirect addressing Register: Memory Pointers:
IRA0,IRA1.
Memory Pointers:
MP0,MP1.

17. Status Register

18. I/O Structure

19. Interrupt Interrupt has priority issue.
Once an interrupt subroutine is serviced, all the other interrupts will be block ( by cleaning the EMI flag).
After the subroutine set the “RETI”, the EMI will be set again.

20. Interrupt control register

21. Interrupt Scheme

22. Timer/Event Counter 0

23. Timer/Event Counter 1

24. Timer Control Register 0

25. Timer Control Register 1

26. 3 modes available for the Timer/Counter
Timer Mode
Event Counter Mode
Pulse Width Mode

27. 4 steps to setup in the Timer Mode
Set to Timer Mode by writing 10 to TM1, TM0
Set the initial timer TMR value
Enable the corresponding interrupt by setting the ETI and EMI bit
Start the Timer by setting the TON bit of the TMRC

28. 5 steps to setup in the Even Counter Mode
Set to Event Counter Mode by writing 01 to TM1, TM0
Select TE=1 to count on the falling edge or TE=0 to count on the rising edge
Set the Timer initial value into TMR
Enable the corresponding interrupt by setting the ETI and EMI bits
Start the Timer by setting the TON bit in the TMRC register

29. 5 steps to setup in the Pulse Width Measurement Mode
Set to Pulse Width Mode by writing 11 to TM1, TM0
Select TE=1 to measure a High Pulse Width and TE=0 to measure a Low Pulse Width
Set the Timer initial value, TMR, usually set to 0H for Pulse Width Measurements 
Enable the corresponding interrupt by setting the ETI and EMI bits
Start the Timer by setting the TON bit in the TMRC

30. PFD and Buzzer PFD is programmable frequency divider.
PFD is pin shared with PA3(selected via configuration optional).
Clock source of PFD is come from timer0 or timer1 overflow signal (selected via configuration optional).
PFD output is controlled by switch on/off PA3.

31. Watchdog Timer
The watchdog timer is provided to prevent program uncontrollable .
3 clock sources can be selected as watchdog timing source: (by configuration)
T1(fsys /4) , 32KHz RTC, WDT OSC output.
At HALT, only WDT OSC or RTC oscillator is still running.

32. Watchdog Register
If watchdog timeout ,the system will be reset. The status bit “TO” will be set.
There are two method of using software to clear watchdog timer (selected by configuration) :
One instruction : CLR WDT
Two instruction : CLR WDT1, CLR WDT2

33. PWM PWM is Pulse Width Modulator.
There are two modes 6+2 or 7+1 selected by configuration.
User can change the duty cycle by software
by writing data to PWM0~PWM3 special data register.
PWM function can be controlled On/Off by software.
Enable PWM output : SET PD0
Disable PWM output : CLR PD0

34. PWM 6+2 Mode

35. PWM 7+1 Mode

36. Analog to Digital Converter
The HT46R24 has a 10-bit ADC.
ADC can be disabled by software.
Max. 4 or 8 channels can input to the ADC.
Channels set in ADCR by software
ADC channels are pin-shared with Port B.
As ADC input or Port B set in ADCR by software
Input range is from 0 to VDD.
Min. ADC clock period is 1 us.
ADC sampling time is 32 ADC clocks.
ADC convert time is 76 ADC clocks.
Max. INL ± 1 LSB.

37. ADC Convert Data Register
ADRL/ADRH are two registers to store the ADC convert data.

38. A/D Convert Control Register

39. A/D Convert Clock Source Register

40. A/D Convert Timing Diagram

41. I2C Bus Interface I2C bus is a bidirectional 2-wire serial interface.
SCL : serial clock pin.
SDA : serial data pin.
I2C output is of open drain . An external pull high resistor is needed.
HT46 series I2C bus is only operates in Slave mode. For Master mode , user can implement by software.

42. Data transfer on the I2C-bus

43. I2C relative Registers I2C Slave Address Register - HADR
I2C Input/Output Data Register – HDR
I2C Control Register –HCR.
I2C Status Register – HSR.

44. HADR Register

45. HDR Register

46. HCR Register

47. HSR Register

48. I2C Bus Communication STEP1 STEP2 STEP3
Write the slave address of the microcontroller to the HADR.
STEP2
Set the HEN(bit7 of HCR) to 1 to enable the I2C bus.
STEP3
Set the EHI(bit2 of INTC1) to 1 to enable I2C interrupt

49. I2C Bus ISR Flow Chart

50. HALT The system oscillator will be turned off.
All of the I/O ports and RAM remain unchanged.
The WDT will be cleared and resume counting if the WDT clock source is selected to come from the WDT oscillator.
The PDF is set and the TO is cleared.

51. How to wake up from HALT mode
External Reset
External Interrupt
Falling edge signal on port A
WDT overflow

52. RESET
Power on reset
Reset pin reset
Low Voltage Reset
WDT reset

53. Power on Reset Power on reset 時間的定義是RESET 上升到VIH後到 MCU 開始執行程式這段時間
這段時間包含三大部分：
第一部分是RESET PIN 上升與 Oscillator 的啟動時間
第二部分是 Oscillator 的穩定時間
第三部分是MCU為了確保 clock 的正確性，再經過1024 個 clock 之後才將 clock 輸入系統
上述三段時間構成了 Power On Reset Time

54. Low Voltage Reset SRC MCU 所搭載的 LVR 規格是 1.8V ~ 2.0V, typical 是 1.9V
如果 VDD 低於 LVR 的電壓範圍，且時間大於 1ms ，則會使 MCU 進入 reset 狀態，直到 VDD 大於 LVR 的範圍，才會讓 MCU 重新工作
但請注意 Note 1 的說明，1024 個 clock 的 delay 時間必須列入計算

55. Register Initial Status (1)

56. Register Initial Status (2)

57. Register Initial Status (3)

58. Application Circuit
其中 Oscillator 所連接的兩個電容(C1,C2)，是為了調整震盪頻率的補償作用，一般的應用皆可省略，除非採用 1MHz 以下的 resonator 或是 crystal，才會用到這兩個電容
至於電容C* 的適當值，可以參考data sheet 的建議值。
VFD MCU 系統頻率的選擇透過 configure option共用三種方式：
是 RC Osc. 外掛電阻如圖右的第一格
是 Crystal Osc. 外掛 resonator 或是 crystal，如圖右的第二格

59. Configuration Options

60. Q & A