1、關(guān)于arm2440中斷源個(gè)數(shù)的一點(diǎn)想法 s3c2440支持多達(dá)36個(gè)內(nèi)部中斷源和24個(gè)外部中斷源，分離用法內(nèi)部終端屏蔽寄存器intmsk和外部中斷寄存器msk舉行屏蔽控制。其中，外部中斷源通過(guò)gpio以復(fù)用的方式成為內(nèi)部中斷源的一部分。 但是我們清晰，intmsk是一個(gè)32位的寄存器，最多只能支持32中斷，它是如何對(duì)應(yīng)這么多中斷的呢?首先我們先看intmsk對(duì)應(yīng)的位。interrupt mask (intmsk) register (continued)int_ 31 0 = service available, 1 = masked 1int_rtc 30 0 = service avail

2、able, 1 = masked 1int_spi1 29 0 = service available, 1 = masked 1int_uart0 28 0 = service available, 1 = masked 1int_iic 27 0 = service available, 1 = masked 1int_h 26 0 = service available, 1 = masked 1int_usbd 25 0 = service available, 1 = masked 1int_on 24 0 = service available, 1 = masked 1int_u

3、art1 23 0 = service available, 1 = masked 1int_spi0 22 0 = service available, 1 = masked 1int_sdi 21 0 = service available, 1 = masked 1int_dma3 20 0 = service available, 1 = masked 1int_dma2 19 0 = service available, 1 = masked 1int_dma1 18 0 = service available, 1 = masked 1int_dma0 17 0 = service

4、 available, 1 = masked 1int_ 16 0 = service available, 1 = masked 1int_uart2 15 0 = service available, 1 = masked 1int_timer4 14 0 = service available, 1 = masked 1int_timer3 13 0 = service available, 1 = masked 1int_timer2 12 0 = service available, 1 = masked 1int_timer1 11 0 = service available, 1

5、 = masked 1int_timer0 10 0 = service available, 1 = masked 1int_wdt_ac97 9 0 = service available, 1 = masked 1int_tick 8 0 = service available, 1 = masked 1nbatt_flt 7 0 = service available, 1 = masked 1int_cam 6 0 = service available, 1 = masked 1eint8_23 5 0 = service available, 1 = masked 1eint4_

6、7 4 0 = service available, 1 = masked 1eint3 3 0 = service available, 1 = masked 1eint2 2 0 = service available, 1 = masked 1eint1 1 0 = service available, 1 = masked 1eint0 0 0 = service available, 1 = masked 1我們發(fā)覺(jué)intmsk的第5，6位對(duì)應(yīng)了eint4_7, eint8_23，20個(gè)外部中斷，也就是所，這20個(gè)gpio引腳只能觸發(fā)這兩個(gè)中斷。但是當(dāng)中斷到來(lái)時(shí)，我們假如推斷是由哪一

7、個(gè)gpio引腳觸發(fā)的呢?這個(gè)時(shí)候我們可以通過(guò)查詢eintmask來(lái)推斷中斷源。eintmask bit descriptioneint23 23 0 = enable interrupt 1= maskedeint22 22 0 = enable interrupt 1= maskedeint21 21 0 = enable interrupt 1= maskedeint20 20 0 = enable interrupt 1= maskedeint19 19 0 = enable interrupt 1= maskedeint18 18 0 = enable interrupt 1= mas

8、kedeint17 17 0 = enable interrupt 1= maskedeint16 16 0 = enable interrupt 1= maskedeint15 15 0 = enable interrupt 1= maskedeint14 14 0 = enable interrupt 1= maskedeint13 13 0 = enable interrupt 1= maskedeint12 12 0 = enable interrupt 1= maskedeint11 11 0 = enable interrupt 1= maskedeint10 10 0 = ena

9、ble interrupt 1= maskedeint9 9 0 = enable interrupt 1= maskedeint8 8 0 = enable interrupt 1= maskedeint7 7 0 = enable interrupt 1= maskedeint6 6 0 = enable interrupt 1= maskedeint5 5 0 = enable interrupt 1= maskedeint4 4 0 = enable interrupt 1= maskedreserved 3:0 reserved但是還有一個(gè)疑問(wèn)，不是說(shuō)60個(gè)中斷源嗎?除去24個(gè)外部中

10、斷源應(yīng)當(dāng)還有60-24 -(32-6)=10個(gè)內(nèi)部中斷源啊。他們?cè)谀哪?其實(shí)這里涉及到了子中斷源的概念。sub sources descriptions sourceint_ac97 ac97 interrupt int_wdt_ac97int_wdt watchdoc interrupt int_wdt_ac97int_cam_p p-port capture interrupt in camera interface int_camint_cam_c c-port capture interrupt in camera interface int_camint_adc_s adc interrupt int_adcint_tc touch screen interrupt (pen up/down) int_adcint_err2 uart2 error interrupt int_uart2int_txd2 uart2 transmit interrupt int_uart2int_rxd2 uart2 receive interrupt int_uart2int_err1 uart1 error interrupt int_uart1int_txd1 uart1 transmit interrupt i nt_uart1int_r