EMIFA总线问题

电路：

EMIFA总线上有nand flash与几片ADC。

问题：

一、

EMIFA总线上的CS3接了nand，而cs0只支持SDRAM，不支持异步设备，那么ADC的片选只能接CS2、CS4、CS5了，是这样么？

二、

现在焊接上一片ADC在CS2上，boot选择从nand启动，启动后加载完uboot后就无法启动了，应该是ADC影响了nand的读取，但是ADC的CS与RD等控制引脚已经与OMAPL138断开了。

输出如下：

Loading from nand0, offset 0x120000

NAND read from offset 120000 failed -74

** Read error

U-Boot >

在上面的情况下，快速的重新掉电、上电，系统又可以启动（而这时，会有极少的机率会无法加载文件系统）

Shine：

1. 是的。

2. 请问是怎么判断ADC影响到了nand的读取。nand flash能正确烧写吗？烧写的时候也是接着ADC的？

user3688025：

回复 Shine:

没有焊接ADC时，从nand启动，是可以启动的，但是焊上了adc后，启动不了。，只是启动到了uboot,如下上面问题里所描述。

在烧写系统到nand的过程中，没有焊接ADC

Shine：

回复 user3688025:

请问uboot也是放在nand flash里的吗？

user3688025：

回复 Shine:

是的

user3688025：

回复 Shine:

有时在内核启动时无法找到nand flash

[ 1.792997] ata1: SATA max UDMA/133 mmio [mem 0x01e18000-0x01e19fff] port 0x100 irq 67[ 1.806825] nand_get_flash_type: second ID read did not match 00,00 against 2c,dc[ 1.814752] No NAND device found[ 1.822454] UBI error: ubi_init: UBI error: cannot initialize UBI, error -19[ 1.830288] spi_davinci spi_davinci.1: DMA: supported[ 1.835448] spi_davinci spi_davinci.1: DMA: RX channel: 18, TX channel: 19, event queue: 0[ 1.846159] m25p80 spi1.0: unrecognized JEDEC id ffffff[ 1.852550] spi_davinci spi_davinci.1: Controller at 0xfef0e000[ 1.862923] CAN device driver interface[ 1.866991] smsc911x: Driver version 2008-10-21[ 1.872109] _regulator_get: smsc911x supply vdd33a not found, using dummy regulator[ 1.880214] _regulator_get: smsc911x supply vddvario not found, using dummy regulator[ 1.987697] smsc911x: Device not READY in 100ms aborting[ 2.038368] davinci_mdio davinci_mdio.0: davinci mdio revision 1.5[ 2.044643] davinci_mdio davinci_mdio.0: detected phy mask fffffffe[ 2.052726] davinci_mdio.0: probed[ 2.056229] davinci_mdio davinci_mdio.0: phy[0]: device davinci_mdio-0:00, driver SMSC LAN8710/LAN8720[ 2.066473] PPP generic driver version 2.4.2[ 2.072559] PPP BSD Compression module registered[ 2.077325] PPP Deflate Compression module registered[ 2.083482] usbcore: registered new interface driver rndis_wlan[ 2.090592] usbcore: registered new interface driver zd1201[ 2.097150] usbcore: registered new interface driver asix[ 2.103478] usbcore: registered new interface driver cdc_ether[ 2.110359] usbcore: registered new interface driver net1080[ 2.116965] usbcore: registered new interface driver rndis_host[ 2.123806] usbcore: registered new interface driver cdc_subset[ 2.130796] usbcore: registered new interface driver zaurus[ 2.137371] usbcore: registered new interface driver cdc_ncm[ 2.148459] ata1: SATA link down (SStatus 0 SControl 300)[ 2.161310] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver[ 2.167794] ohci ohci.0: DA8xx OHCI[ 2.171831] ohci ohci.0: new USB bus registered, assigned bus number 1[ 2.178618] Waiting for USB PHY clock good…[ 2.183170] ohci ohci.0: irq 59, io mem 0x01e25000[ 2.240797] hub 1-0:1.0: USB hub found[ 2.244698] hub 1-0:1.0: 1 port detected[ 2.250950] Initializing USB Mass Storage driver…[ 2.256970] usbcore: registered new interface driver usb-storage[ 2.263248] USB Mass Storage support registered.[ 2.269604] usbcore: registered new interface driver usbserial[ 2.275534] usbserial: USB Serial Driver core[ 2.280827] USB Serial support registered for GSM modem (1-port)[ 2.288038] usbcore: registered new interface driver option[ 2.293847] option: v0.7.2:USB Driver for GSM modems[ 2.299462] gadget: Mass Storage Function, version: 2009/09/11[ 2.305490] gadget: Number of LUNs=1[ 2.309326] lun0: LUN: removable file: (no medium)[ 2.314356] gadget: Mass Storage Gadget, version: 2009/09/11[ 2.320274] gadget: userspace failed to provide iSerialNumber[ 2.326206] gadget: g_mass_storage ready[ 2.330343] musb-hdrc musb-hdrc: MUSB HDRC host driver[ 2.335648] musb-hdrc musb-hdrc: new USB bus registered, assigned bus number 2[ 2.345573] hub 2-0:1.0: USB hub found[ 2.349935] hub 2-0:1.0: 1 port detected[ 2.357664] mousedev: PS/2 mouse device common for all mice[ 2.364528] _regulator_get: spi1.1 supply vcc not found, using dummy regulator[ 2.372692] ads7846 spi1.1: touchscreen, irq 145[ 2.379064] input: ADS7846 Touchscreen as /devices/platform/spi_davinci.1/spi_master/spi1/spi1.1/input/input0[ 2.392952] omap_rtc omap_rtc: rtc core: registered omap_rtc as rtc0[ 2.399719] omap_rtc: RTC power up reset detected[ 2.405251] i2c /dev entries driver[ 2.410605] Linux video capture interface: v2.00[ 2.423638] ov2640 1-0030: Product ID error 87:87[ 2.429311] vpif_capture vpif_capture: Error registering v4l2 subdevice[ 2.439545] usbcore: registered new interface driver uvcvideo[ 2.445351] USB Video Class driver (1.1.1)[ 2.450279] watchdog watchdog: heartbeat 60 sec[ 2.456645] cpuidle: using governor ladder[ 2.461490] cpuidle: using governor menu[ 2.468736] davinci_mmc davinci_mmc.0: Using DMA, 4-bit mode[ 2.480448] usbcore: registered new interface driver usbhid[ 2.486080] usbhid: USB HID core driver[ 2.490603] _regulator_get: ad7606-8.0 supply vcc not found, using dummy regulator[ 2.504065] timer clk rate(156000000)[ 2.508890] iio_davinci_tmr_trigger iio_davinci_tmr_trigger.0: iio trigger davinci TMR2, IRQ-68[ 2.520677] usbcore: registered new interface driver snd-usb-audio[ 2.533659] soc-audio soc-audio.0: ASoC: Failed to create card debugfs directory[ 2.541894] _regulator_get: 1-0018 supply IOVDD not found, using dummy regulator[ 2.549729] _regulator_get: 1-0018 supply DVDD not found, using dummy regulator[ 2.557282] _regulator_get: 1-0018 supply AVDD not found, using dummy regulator[ 2.564984] _regulator_get: 1-0018 supply DRVDD not found, using dummy regulator[ 2.580816] asoc: tlv320aic3x-hifi <-> davinci-mcasp.0 mapping ok[ 2.588526] usb 1-1: new full-speed USB device number 2 using ohci[ 2.598686] ALSA device list:[ 2.601710] #0: DA850/OMAP-L138 EVM[ 2.605770] TCP cubic registered[ 2.609383] NET: Registered protocol family 17[ 2.613974] can: controller area network core (rev 20090105 abi 8)[ 2.620569] NET: Registered protocol family 29[ 2.625100] can: raw protocol (rev 20090105)[ 2.629516] can: broadcast manager protocol (rev 20090105 t)[ 2.635270] can: netlink gateway (rev 20101209)[ 2.641136] lib80211: common routines for IEEE802.11 drivers[ 2.647226] _regulator_get: deviceless supply cvdd not found, using dummy regulator[ 2.662334] console [netcon0] enabled[ 2.666043] netconsole: network logging started[ 2.675294] omap_rtc omap_rtc: setting system clock to 2000-01-01 00:00:00 UTC (946684800)[ 2.684971] VFS: Cannot open root device "ubi0_0" or unknown-block(0,0)[ 2.691800] Please append a correct "root=" boot option; here are the available partitions:[ 2.700343] Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(0,0)