HT819D0 4.2 Second LOG-PCM Speech Features • • • • • • • • • • Operating voltage: 2.4V~5.0V Directly drives an external transistor Low standby current (1µA typ. for VDD=3V) Minimal external components 252 words table ROM for key functions Programmable silence length and end-pulse width (minimal end-pulse width is 330µs at a 6kHz sampling rate) 4.2-second voice capacity Section options: – Retriggerable – Non-retriggerable FLAG1 options: – End-pulse output – 3HzB flash – 6HzB flash – Voice output indication – Busy output • FLAG2 options: – 3Hz flash – 6Hz flash – Busy output Controllable volume 6 keys Key options: – Stop key: KEY6 – Random (only for KEY1) – Sequential (only for KEY1) – Repeat (for all KEYs) – Key debounce time (for all KEYs): 700µs, 22ms, 45ms, 180ms (based on a 6kHz sampling rate of) – One shot (for all KEYs) – Pull-high resistance (for all KEYs) Dice form or 16-pin DIP/SOP • • Alert and warning system Sound effect generators • • • Applications • • • Toys Alarm clocks Public address system General Description The customer’s voice sources are recorded section by section into an internal mask ROM. The sectional playback arrangement instructions of each key are stored in the table ROM. The key features are also programmable. With such a flexible structure, the HT819D0 is excellent for versatile voice applications. The HT819D0 is a single chip LOG-PCM voice synthesizer LSI with 4.2-second voice capacity at a 6kHz sampling rate. The chip when triggered drives a speaker through an external transistor with a current switch D/A converter output. Negligible current will be consumed in the standby state. The HT819D0 provides 6 key inputs and 2 programmable FLAG outputs. With a 2.4V~5.0V power supply, a complete synthesized voice playback system can be easily built with very few external components. 1 6th May ’98 HT819D0 Pin Assignment Block Diagram Unit: µm Pad Coordinates Pad No. X Y 1 2 3 4 5 6 7 –885.05 –885.05 –1005.05 –229.95 62.35 526.75 833.85 522.30 344.50 –710.50 –660.50 –660.50 –660.50 –660.50 Pad No. 8 9 10 11 12 13 X Y 1008.85 –710.50 905.45 660.50 628.05 660.50 296.45 660.50 –333.95 660.50 –665.55 660.50 Chip size: 2290 × 1750 (µm)2 * The IC substrate should be connected to VSS in the PCB layout artwork. Pin Description Pin No. Pin Name I/O Internal Connection 1 OSC1 I — 2 FLAG1 O NMOS Open Drain 3 VSS I — 4 FLAG2 O NMOS Open Drain 5, 12, 13 NC — — Description Oscillator input pin 3HzB/6HzB flash output, busy output, end-pulse or voice output indication (by code option). Open drain, active low output Negative power supply (GND) 3Hz/6Hz flash output or busy output (by code option). Open drain, active low output No connection 2 6th May ’98 HT819D0 Pin Name I/O Internal Connection Description 6~11 KEY1~KEY6 I Pull-High Trigger key, low active. Key features such as debounce time, pull-high resistance and repeat are all by mask option. 14 VDD I — 15 AUD O PMOS Open Drain 16 OSC2 O — Pin No. Positive power supply Voice output for driving an external transistor Oscillator output pin Absolute Maximum Ratings* Supply Voltage ............................... –0.3V to 6V Storage Temperature ............... –50°C to 125°C Input Voltage ............... VSS–0.3V to VDD+0.3V Operating Temperature ............. –20°C to 70°C *Note: These are stress ratings only. Stresses exceeding the range specified under “Absolute Maximum Ratings” may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability. (Ta=25°C) Electrical Characteristics Symbol Parameter Test Conditions VDD Conditions — Min. Typ. Max. Unit 2.4 — 5.0 V — 200 400 µA — 1 3 µA VDD Operating Voltage — IDD Operating Current 3V ISTB Standby Current 3V IO Max. AUD Output Current 3V VOH=0.6V –1.5 –2 — mA IOL FLAG Sink Current 3V VOL=0.3V 1.5 3.0 — mA VIH “H” Input Voltage — — 0.8VDD — VDD V VIL “L” Input Voltage — — 0 — 0.2VDD V fOSC Oscillating Frequency 3V ROSC=530kΩ 76 96 116 kHz No load, fOSC=96kHz — 3 6th May ’98 HT819D0 Functional Description The HT819D0 is a mask ROM type voice synthesizer with 4.2-second voice capacity. A group of pre-recorded voice sections is played upon receipt of key trigger input signals. Two FLAG signals are output while playing voices. Play function block diagram The 4.2-second voice capacity can be divided into sections of arbitrary length. Notice that the silence length and end-pulse width are not included in the memory. By using HOLTEK’s programming tools, the contents and arrangement of sections, as well as key features and FLAG output are all programmable before device fabrication. Voice ROM The IC provides 6 key inputs (KEY1~KEY6). Of the 6 keys, KEY1 can be optioned as a direct, sequential or random trigger key. KEY6 can be selected as a stop or direct key. The remaining 5 keys (KEY2~KEY6), are used as direct keys exclusively. The voice ROM is originally designed to continuously record the 4.2-second voice data at a 6kHz sampling rate. A higher sampling rate will generate voices of better playback quality, but will shorten the total recording time. On the other hand, a lower sampling rate results in longer recording time but sacrifice voice quality. System oscillator The playback time can be significantly extended by making use of coding efficiency, silence playing, section repeating, section cascade, etc. The HT819D0 has a built-in RC oscillator which requires only one external resistor for normal applications. The oscillator frequency is typically 96kHz for an external resistor of 530kΩ. The required oscillator frequency may vary with different sampling rates in the process of voice programming. As a result, the value of the oscillator resistor may be different for different items. Section Section is the basic element constituting the contents of voice ROM. During programming, the customer’s voice sources can be divided into as many sections as required. A section can be comprised by a voice or an interval of silence. However, the silent length is not counted in voice ROM. The total number of sections included should be less than 252 due to the space limitation of the function table ROM. The total length of the included sections is limited by the voice ROM. The oscillator is turned on when triggered by a key input. After playing, it is immediately turned off and the chip goes into the standby state. A section, when triggered by a key input, can be played once, repeatedly or cascaded with other sections, depending on the key function table instructions. 4 6th May ’98 HT819D0 The following are examples of section division: Key function table The sections included in the voice ROM are played according to the instructions of the key function table. The function table contains group information as well as playing order of sections in the groups. Notice that the total number of sections included in the groups should be less than 252–the space limitation of the function table ROM. • KEY1 as a direct key Each key is mapped to a group in the function table. If a key is not used, the group mapped to that key is a piece of silence. The following is an example of the function table: In addition, a section can be set as retriggerable or non-retriggerable depending on the code option. • Retriggerable When the currently playing section is set as retriggerable, it will stop immediately upon receipt of other key inputs. Group 1 sec.1 + sec.2 + sec.3 + sec.5 Group 2 sec.3 Group 3 sec.2 + sec.2 + sec.3 + sec.4 Group 4 sec.5 + sec.3 As illustrated in the above table, the voice ROM is composed of 5 sections and the function table of 11 sections. If KEY1 is momentarily triggered, section 1, section 2, section 3 and section 5 are played in sequence and then stops. Triggering KEY2 plays section 3, and so on. • Non-retriggerable When the currently playing section is selected as non-retriggerable, it will go on playing till the whole section is completed, whether or not there is a key input in the process of playing. For a key group, some sections can be set as retriggerable and some as non-retriggerable. When a retriggerable section of a key group is playing, any key can be triggered to interrupt its playing. On the other hand, if it is a nonretriggerable section playing, any key interrupt is ignored. • KEY1 as a sequential or random key When KEY1 is optioned as a sequential or random key, it can include multiple groups (subgroups) in the function table. However, the remaining 5 keys (KEY2~KEY6) are used as direct keys exclusively and comprise only one group in the function table. Group An example is shown below: The HT819D0 plays groups according to the key input. A group can be made up of one or more sections. When a key is triggered, the corresponding group is played. For example, triggering KEY2 plays group 2, and so on. The same section is allowed to appear in different groups. However, KEY1 can be made up of multiple groups when it is optioned as a sequential or random key. Otherwise, each key is comprised by one group only. Group 1-1 sec.4 + sec.2 Group 1-2 sec.1 + sec.3 : : : : Group 1-N sec.2 + sec.3 5 Group 2 sec.2 + sec.3 Group 3 sec.3 + sec.5 Group 4 sec.1 + sec.5 + sec.2 6th May ’98 HT819D0 features of KEY1 have to be set in the following ways: As indicated on the table, KEY1 can be made up of sub-groups. Each time KEY1 is triggered, the corresponding sub-groups are played in sequence. ♦ ♦ ♦ ♦ sequential or random retriggerable – minimum key debounce time (≅700µs, fOSC=96kHz) For instance, if sub-group 1-3 is the previous playing group, sub-group 1-5 will start playing after 2 pulses are applied to KEY1, and so on. – – The playing sequence of sequential KEY1 is: Group 1-1 → Group 1-2 → Group 1-3 ..... → Group 1-N (the last group) →Group 1-1 ..... The playing sequence of random KEY1 is: Group 1-3 → Group 1-5 ..... → Group 1-N → Group 1-3 → Group 1-5 ..... That KEY1 functions as a random key is a special case of sequential key, which combines a particular arrangement of sub-group playing sequence. To make easy selection of KEY1 sub-groups, one of KEY2~KEY6 should be programmed as silence. Then this silence key has to be triggered to reset KEY1. By so doing, the playing sub-group is directly specified by the pulse number applied to KEY1 (see Figure 2). Reset of KEY1 playing sequence If a sub-group of KEY1 group is being played and one of KEY2~KEY6 is triggered, the playing sub-group will be terminated, and the newly triggered key group is played instead. The first sub-group will start playing when KEY1 is retriggered. In other words, the KEY1 playing sequence is reset whenever a key other than KEY1 is triggered (see Figure 1). • KEY6 as a stop key (by mask option) When KEY6 functions as a stop key, any voice output can be stopped by pressing KEY6. • KEY1~KEY5 as a repeat key KEY1~KEY5 all function as a repeat key if one of the 5 keys is set as a repeat key. In other words, once the mode of one of KEY1~KEY5 is determined, the remaining four keys are set accordingly. Sub-group selection When KEY1 is triggered with pulses, the desired sub-group can be selected by controlling its corresponding pulse number. However, the As a repeat key, the sections included can be played sequentially and repeatedly till key input is triggered. KEY6 has no other choice Figure 1 Reset of KEY1 playing sequence Figure 2 KEY1 sub-group selection 6 6th May ’98 HT819D0 When the FLAG1 and FLAG2 pins are optioned as 3HzB and 3Hz outputs, they will be alternately output at a 3Hz rate. but functions as a stop key when KEY1~KEY5 are set as repeat keys. Key features • Key priority When two or more keys are triggered simultaneously, the output voice is determined by the key priority as shown below: KEY1>KEY2>......KEY5>KEY6 • Key debounce time • 6Hz/6HzB flash There are four kinds of key-in debounce time that can be selected by mask option, namely, 700µs, 22ms, 45ms and 180ms. The key debounce time varies with the value of the system frequency. When voices are playing, the FLAG1 as well as FLAG2 pin outputs a 6Hz signal to drive an LED. The signal is active low, 25% duty. Once the voice output is terminated, the FLAG1 and FLAG2 pins becomes floating outputs. When the FLAG1 and FLAG2 pins are optioned as 6HzB and 6Hz outputs, they will be alternately output at a 6Hz rate. • Pull-high resistance Four kinds of key input pin pull-high resistance can be selected by mask option, namely, 20kΩ, 50kΩ, 100kΩ and 200kΩ. The resistance may vary with VDD, temperatures and the chip itself due to process variations. • Trigger mode All of the six keys are internally set as oneshot trigger mode. • Busy output FLAG When a voice group is playing, the outputs of both FLAG1 and FLAG2 are turned low, indicating that the chip is busy. When voices are playing, both FLAG1 and FLAG2 pins are activated to output one of the following signals through code option. FLAG1 can be optioned as one of the following signal outputs: None, 3HzB flash, Busy, 6HzB flash, Voice indicator, or End-pulse output FLAG2, on the other hand, can be set as one of the following signal outputs: None, 3Hz flash, 6Hz flash, or Busy output In addition to the above-stated output signals, FLAG1 can also generate one of the following signals by code option: • 3Hz/3HzB flash When voices are playing, the FLAG1 as well as FLAG2 pin outputs a 3Hz signal to drive an LED. The signal is active low, 25% duty. Once the voice output is terminated, the FLAG1 and FLAG2 pins become floating outputs. 7 6th May ’98 HT819D0 • Voice indicator output The FLAG1 as well as FLAG2 pins are both floating outputs when the chip is in the standby state. FLAG1 is active low when voices are playing. FLAG1 is also turned low when a voice section is output. FLAG1 becomes a floating output after the silence section is output or the voice output is terminated. Volume control The function of volume control can be set by mask option. A code is written in the function table for the purpose of controlling the volume of each section output after the volume control function is chosen. There are two volume options, namely, full range and half range. AUD The AUD pin is a PMOS open drain structure. It outputs voice signals to drive a speaker through an external NPN transistor when the chip is active. The AUD pin becomes a floating output when the chip is in the standby state. • End-pulse output The FLAG1 pin outputs an active low pulse when the voice output is completed. The pulse width can be programmed depending on the customer’s requirements. The 8050 type transistor with hFE≅150 is recommended for an output driver. Timing Diagram One key operation • Sequential-retriggerable • Sequential-nonretriggerable 8 6th May ’98 HT819D0 • Random-retriggerable • Random-nonretriggerable Note: Group 1-N may be any of the KEY1 groups Multi-key operation • Retriggerable 9 6th May ’98 HT819D0 • Non-retriggerable • Repeat Note: M, N=1:6 10 6th May ’98 HT819D0 Application Circuits General application Parallel application Cascade or external driving 11 6th May ’98 HT819D0 Power-on play (one shot) Power-on play (continuous) With volume adjustment 12 6th May ’98 HT819D0 Push-pull output To prevent the speaker and driver transistor from damage due to excess power consumption which results from a high voltage power supply (4.5V~5.5V), the following push-pull output stage is recommended. Coupling to power amplifier Standard Item List Item HT819D1 Name ROSC Remarks 460kΩ Animal Voice 13 6th May ’98