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Basic Information
Question 1
What are the devices in the HT49CVx/RVx 8-bit VFD MCU range and what are their most important specs?
Answer
The HT49xV3, HT49xV5, HT49xV7 and HT49xV9, are the devices which form Holtek's series of 8-bit MCU VFD devices. They can be subdivided according to Program Memory capacity of 2Kx16, 4Kx16, 8Kx16 and 16Kx16 as well as 96x8, 192x8, 384x8 and 768x8 Data Memory capacity respectively. Each device in the series contains two 16-bit Timer/Event Counters and an SIO serial port function, which allows for easy interfacing to other external devices. The devices also incorporate a Buzzer/PFD function which can be used as an audio frequency generator and an RMT Remote Control Timer which can be used to decode IR remote control input signals. The devices also support an RTC oscillator, which can maintain timer operation even when the devices are in the Power Down Mode. The VFD function uses RAM mapping, allowing for easy interfacing to application VFD panels and easy writing and erasing of related display data. Additionally the HT49xVx series (HT49xV3 excepted) have an internal 8-bit x 4 or 10-bit x 8 A/D function and 8-bit PWM function.
| Part
No. |
VDD |
System
Clock |
Program
Memory |
Data
Memory |
I/O |
SEG |
Grid |
Timer |
Interrupt |
SIO |
A/D |
PWM |
Stack |
Package |
| 16-bit |
RTC |
RMT |
Ext. |
Int. |
HT49RV3
HT49CV3 |
2.2V~
5.5V |
400kHz~
8MHz |
2Kx16 |
96x8 |
17 |
11~
16 |
11~
4 |
2 |
v |
v |
2 |
5 |
v |
-- |
-- |
6 |
52QFP |
HT49RV5
HT49CV5 |
2.2V~
5.5V |
400kHz~
8MHz |
4Kx16 |
192x8 |
20 |
11~
16 |
11~
4 |
2 |
v |
v |
2 |
6 |
v |
8-bitx4 |
8-bitx2 |
8 |
56SSOP |
HT49RV7
HT49CV7 |
2.2V~
5.5V |
400kHz~
8MHz |
8Kx16 |
384x8 |
32 |
11~
16 |
11~
4 |
2 |
v |
v |
2 |
6 |
v |
10-bitx8 |
8-bitx4 |
16 |
100QFP |
HT49RV9
HT49CV9 |
2.2V~
5.5V |
400kHz~
8MHz |
16Kx16 |
768x8 |
32 |
12~
20 |
16~
8 |
2 |
v |
v |
2 |
6 |
v |
10-bitx8 |
8-bitx4 |
16 |
100QFP |
Question 2
What are the various packages available in the HT49xVx series of
MCUs?
Answer
| HT49CV3 / HT49RV3 : |
52QFP |
| HT49CV5 / HT49RV5 : |
56SSOP |
| HT49CV7 / HT49RV7 : |
100QFP |
| HT49CV9 / HT49RV9 : |
100QFP |
Question 3
What is the operating frequency of the HT49xVx A/D with VFD type
MCUs?
Answer
For a VDD voltage of between 3.3V and 5.5V the maximum operating frequency is 8MHz. For a
VDD voltage of between 2.2V and 3.2V the maximum operating frequency is 4MHz.
Functional Description
Question 1
How is the 16-bit timer setup?
Answer
The 16-bit timer/counter is a count up counter, which upon reaching a value of 65535 (0FFFFH) will reset itself to 0000H and generate an internal interrupt signal. To obtain different timer counts, say N, of less than 65536, the timer should be first preset with a fixed value of 65536-N. After setting up this preset value the timer should be activated which will enable it to count from this preset value to 65535. The value that the timer is to count N, is therefore given by the formula 65536-(65536-N)=N.
Question 2
What is the access sequence of the 16-bit Timer/Counter?
Answer
For the HT49xVx A/D with VFD type MCU, the internal data bus is 8-bit wide, therefore for the 16-bit Timer/Counter, the user has to write the Low Byte data first and then write the high byte data. To read the Timer/Counter contents, the user has to first read the High Byte data first and then the Low Byte data.
Application Description
Question 1
In what kind of products is it possible to use the HT49xVx devices?
Answer
The HT49xVx range of devices are industrial standard devices which are especially applicable for products which incorporate a VFD display such as
DVD/VCD players, automotive compass/head-up display products or household electrical appliances with VFD displays. In addition another application is in the controller for PC multi-media case displays.
Question 2
What kind of VFD panels does the HT49xVx devices support?
Answer
The HT49xV3 / HT49xV5 / HT49xV7 devices support 16-segment & 4-grid to 11-segment & 11-grid VFD panels, while the HT49xV9 device supports 20-segment & 8-grid to 12-segment & 16-grid panels.
Question 3
If the RC oscillator is selected as the system clock, what are the purposes of the external resistor and capacitor? Can the capacitor be omitted?
Answer
The external resistor on the OSC1 pin is used to generate bias to control the internal RC charge and discharge. The frequency of the RC oscillator is determined by the value of this external resistor. The value of this resistor is from 24KΩ to 1MΩ. The recommended 470pF external capacitor, which is connected to the OSC1 pin, is added to avoid cross-talk to the OSC2 line. The OSC2 pin is provided to supply an output frequency of 1/4 system frequency. However, if this 1/4 system frequency output, OSC2, is not utilized, the external capacitor on OSC1 pin can be omitted.
Question 4
When using the tools to change the value of bits in the PA port register from "0" to "1", why when after checking the content of the register, I cannot see that the PA pin has changed its value.
Answer
When changing a specific bit value on the PA data register, only bits that are setup as outputs will be changed. Bits to be changed must first be setup as outputs by writing a zero to the corresponding bit of the PAC register.
Question 5
How can the RTC in the HT49CV5 MCU be used?
Answer
- First select the clock source from the configuration options
- According to needs, select the RTC division ration. fRTC=fS/28~215
Note that fS is the clock source in the previous item.
- According to the needs of the interrupt setup the interrupt enable flags: EMI = 1, EMFI = 1 and
ERTI=1
When the above has been setup, the RTC will run continuously. Each time the RTC times-out, the RCT flags will be set as follows: MFF = 1 and RTF = 1 and the related interrupt will be generated. After the interrupt routine has finished, the RTF should be cleared by the program.
Points to Note
Question 1
In the HT46 series, when the tools are in the software simulation mode and not the emulation mode, is it possible to still simulate the internal analog to digital converter?
Answer
It is not possible to simulate the action of the A/D converter if in the software simulation mode. The A/D converter can only be simulated by the ICE hardware and therefore the tools must be in the emulation mode.
Others
Question 1
What kind of development tools does Holtek provide for the HT49xVx series of
MCUs?
Answer
Holtek supplies a multi-functional full suite of software and hardware development tools for these devices. They include the HT-ICE hardware emulator and OTP writer, the HT-3000 software, the HT-ICE interface card, OTP adapter cards for different IC packages and a USB interface adapter cable.
Question 2
What are the ESD and Latch up features of the HT49xVx A/D with VFD type
MCUs?
Answer
As the HT49xVx A/D with VFD type series of MCUs possess exceptional ESD and Latch up protection they are suitable for industrial use. In the area of ESD protection the devices conform to the US military spec MIL-STD-883E 3015.7 and each I/O can withstand in excess of 5KV of body static. Regarding latch-up, the devices conform to the JEDEC-NO.17 specification, when tested in
current mode, each I/O can withstand in excess of 100mA.
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