---
title: getDDCBlock
framework: kernel
role: pseudoSymbol
path: kernel/ioframebuffer/1813183-getddcblock
---

# getDDCBlock

Return display EDID data.

## Declaration

```occ
virtual IOReturn getDDCBlock(
 IOIndexconnectIndex,
 UInt32blockNumber, 
 IOSelectblockType,
 IOOptionBitsoptions, 
 UInt8 *data,
 IOByteCount *length ); 
```

## Parameters

- `connectIndex`: Index of the display connection, from zero to the value of getConnectionCount().
- `blockNumber`: Block number, ranging from one to the number of blocks return by the display.
- `blockType`: kIODDCBlockTypeEDID will be passed.
- `options`: No options are currently defined.
- `data`: Caller allocated buffer to receive the blocks data.
- `length`: In/out parameter - callers allocated buffer size, driver returns actual size.

## Return Value

Return Value An IOReturn code.

## Overview

Overview Hardware that supports DDC/EDID display sensing should implement this method to return EDID data in 128 byte blocks.

## See Also

### Miscellaneous

- [connectFlags](kernel/ioframebuffer/1812972-connectflags.md)
- [convertCursorImage](kernel/ioframebuffer/1812983-convertcursorimage.md)
- [doI2CRequest](kernel/ioframebuffer/1812996-doi2crequest.md)
- [enableController](kernel/ioframebuffer/1813011-enablecontroller.md)
- [flushCursor](kernel/ioframebuffer/1813022-flushcursor.md)
- [getApertureRange](kernel/ioframebuffer/1813036-getaperturerange.md)
- [getAppleSense](kernel/ioframebuffer/1813053-getapplesense.md)
- [getAttribute](kernel/ioframebuffer/1813070-getattribute.md)
- [getAttributeForConnection](kernel/ioframebuffer/1813093-getattributeforconnection.md)
- [getConnectionCount](kernel/ioframebuffer/1813110-getconnectioncount.md)
- [getCurrentDisplayMode(IODisplayModeID *, IOIndex *)](kernel/ioframebuffer/1813145-getcurrentdisplaymode.md)
- [getDisplayModeCount](kernel/ioframebuffer/1813210-getdisplaymodecount.md)
- [getDisplayModes](kernel/ioframebuffer/1813237-getdisplaymodes.md)
- [getInformationForDisplayMode](kernel/ioframebuffer/1813269-getinformationfordisplaymode.md)
- [getPixelFormats](kernel/ioframebuffer/1813303-getpixelformats.md)
- [getPixelFormatsForDisplayMode](kernel/ioframebuffer/1813329-getpixelformatsfordisplaymode.md)
- [getPixelInformation](kernel/ioframebuffer/1813353-getpixelinformation.md)
- [getStartupDisplayMode](kernel/ioframebuffer/1813382-getstartupdisplaymode.md)
- [getTimingInfoForDisplayMode](kernel/ioframebuffer/1813413-gettiminginfofordisplaymode.md)
- [getVRAMRange](kernel/ioframebuffer/1813443-getvramrange.md)
- [handleEvent](kernel/ioframebuffer/1813481-handleevent.md)
- [hasDDCConnect](kernel/ioframebuffer/1813510-hasddcconnect.md)
- [readDDCClock](kernel/ioframebuffer/1813550-readddcclock.md)
- [readDDCData](kernel/ioframebuffer/1813593-readddcdata.md)
- [registerForInterruptType](kernel/ioframebuffer/1813622-registerforinterrupttype.md)
- [setApertureEnable](kernel/ioframebuffer/1813646-setapertureenable.md)
- [setAttribute](kernel/ioframebuffer/1813661-setattribute.md)
- [setAttributeForConnection](kernel/ioframebuffer/1813672-setattributeforconnection.md)
- [setCLUTWithEntries](kernel/ioframebuffer/1813680-setclutwithentries.md)
- [setCurrentDisplayMode](kernel/ioframebuffer/1813685-setcurrentdisplaymode.md)
- [setCursorImage](kernel/ioframebuffer/1813692-setcursorimage.md)
- [setCursorState](kernel/ioframebuffer/1813699-setcursorstate.md)
- [setDDCClock](kernel/ioframebuffer/1813707-setddcclock.md)
- [setDDCData](kernel/ioframebuffer/1813718-setddcdata.md)
- [setDetailedTimings](kernel/ioframebuffer/1813724-setdetailedtimings.md)
- [setDisplayMode](kernel/ioframebuffer/1813732-setdisplaymode.md)
- [setGammaTable](kernel/ioframebuffer/1813739-setgammatable.md)
- [setInterruptState](kernel/ioframebuffer/1813744-setinterruptstate.md)
- [setStartupDisplayMode](kernel/ioframebuffer/1813749-setstartupdisplaymode.md)
- [unregisterInterrupt(void *)](kernel/ioframebuffer/1813753-unregisterinterrupt.md)
- [unregisterInterrupt(void *, UInt32)](kernel/ioframebuffer/1813757-unregisterinterrupt.md)
- [validateDetailedTiming](kernel/ioframebuffer/1813761-validatedetailedtiming.md)