 |
数据搜索系统，热门电子元器件搜索 |
|
|
数据搜索系统，热门电子元器件搜索 |
|
HT95C40P 数据表(PDF) 15 Page - Holtek Semiconductor Inc |
|
|
|||||||||||||||||||||||||||||
HT95C40P 数据表(HTML) 15 Page - Holtek Semiconductor Inc |
|
|
15 / 52 page  HT95LXXX Rev. 1.20 15 May 26, 2004 routine call to location 0CH will occur. The interrupt request flag T1F and EMI bits will be cleared to disable further interrupts. The real time clock interrupt is generated by a 1Hz RTC generator. When the RTC time-out occurs, the interrupt request flag RTCF will be set. When the RTC interrupt is enabled, the stack is not full and the RTCF is set, a sub- routine call to location 14H will occur. The interrupt re- quest flag RTCF and EMI bits will be cleared to disable other interrupts. The dialer I/O interrupt is triggered by any edge transi- tion onto HKS pin or a falling edge transition onto HDI pin or a rising edge transition onto HFI pin, the interrupt request flag DRF will be set. When the dialer I/O inter- rupt is enabled, the stack is not full and the DRF is set, a subroutine call to location 18H will occur. The interrupt request flag DRF and EMI bits will be cleared to disable other interrupts. Note: 1. If the dialer status is on-hook and hold-line, the falling edge transition onto HDI pin will not generate the dialer I/O interrupt. 2. The HDI input is supported for HT95L400/40P, HT95L300/30P, HT95L200/20P, HT95L100/10P. 3. The dialer I/O interrupt will be disabled when the operation mode is in Idle mode. During the execution of an interrupt subroutine, other in- terrupt acknowledge signals are held until the RETI in- struction is executed or the EMI bit and the related interrupt control bit are set to 1 (if the stack is not full). To return from the interrupt subroutine, ²RET² or ²RETI² may be invoked. RETI will set the EMI bit to enable an interrupt service, but RET will not. Interrupts, occurring in the interval between the rising edges of two consecutive T2 pulses, will be serviced on the latter of the two T2 pulses, if the corresponding inter- rupts are enabled. In the case of simultaneous requests the following table shows the priority that is applied. These can be masked by resetting the EMI bit. Interrupt Source Priority Vector External interrupt 1 04H Timer/Event Counter 0 interrupt 2 08H Timer/Event Counter 1 interrupt 3 0CH Real time clock interrupt 4 14H Dialer I/O interrupt 5 18H Priority of the Interrupt EMI, EEI, ET0I, ET1I, ERTCI and EDRI are used to con- trol the enabling/disabling of interrupts. These bits pre- vent the requested interrupt from being serviced. Once the interrupt request flags (EIF, T0F, T1F, RTCF, DRF) are set by hardware or software, they will remain in the INTC0 or INTC1 registers until the interrupts are ser- viced or cleared by a software instruction. It is recommended that a program should not use the ²CALL subroutine² within the interrupt subroutine. Inter- rupts often occur in an unpredictable manner or need to be serviced immediately in some applications. If only one stack is left and enabling the interrupt is not well controlled, the original control sequence will be dam- aged once the ²CALL² operates in the interrupt subrou- tine. Oscillator Configuration There are two oscillator circuits in the controller, the ex- ternal 32768Hz crystal oscillator and internal WDT OSC. The 32768Hz crystal oscillator and frequency-up con- version circuit (32768Hz to 3.58MHz) are designed for dual system clock source. It is necessary for frequency conversion circuit to add external RC components to make up the low pass filter that stabilize the output fre- quency 3.58MHz (see the oscillator circuit). The WDT OSC is a free running on-chip RC oscillator, and no external components are required. Even if the system enters the Idle mode (the system clock is stopped), the WDT OSC still works within a period of 78 ms normally. When the WDT is disabled or the WDT source is not this RC oscillator, the WDT OSC will be disabled. Watchdog Timer - WDT The WDT clock source is implemented by a WDT OSC or external 32768Hz or an instruction clock (system clock divided by 4), determined by the mask option. This timer is designed to prevent a software malfunction or sequence from jumping to an unknown location with un- predictable results. The Watchdog Timer can be dis- abled by mask option. If the Watchdog Timer is disabled, all the executions related to the WDT result in no opera- tion. If the device operates in a noisy environment, using the on-chip WDT OSC or 32768Hz crystal oscillator is strongly recommended. When the WDT clock source is selected, it will be first di- vided by 512 (9-stage) to get the nominal time-out pe- riod. By invoking the WDT prescaler, longer time-out periods can be realized. Writing data to WS2, WS1, WS0 can give different time-out periods. X 1 X 2 X C 1 5 k W 3 n F 5 0 n F System Oscillator Circuit |
|
链接网址 |
| ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 数据表链接 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Chinese ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
