mrd - 2022.1 English

Vitis Unified Software Platform Documentation: Embedded Software Development (UG1400)

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2022.1 English

Memory read.


mrd [options] <address> [num]

Read <num> data values from the active target's memory address specified by <address>.


Option Description
-force Overwrite access protection. By default accesses to reserved and invalid address ranges are blocked.
-size <access-size> <access-size> can be one of the values below: b = Bytes accesses h = Half-word accesses w = Word accesses d = Double-word accesses Default access size is w. Address is aligned to access-size before reading memory, if the '-unaligned-access' option is not used. For targets that do not support double-word access, the debugger uses two word accesses. If the number of data values to be read is more than 1, the debugger selects the appropriate access size. For example, 1. mrd -size b 0x0 4 Debugger accesses one word from the memory, displays four bytes. 2. mrd -size b 0x0 3 Debugger accesses one half-word and one byte from the memory, displays three bytes. 3. mrd 0x0 3 Debugger accesses three words from the memory and displays three words. To read more than 64 bits of data, specify the number of data words along with the address. Data read is in multiples of access size. For example, to read 128 bits of data, run "mrd -size d <addr> 2" or "mrd -size w <addr> 4".
-value Return a Tcl list of values, instead of displaying the result on the console.
-bin Return data read from the target in binary format.
-file <file-name> Write binary data read from the target to <file-name>.
-address-space <name> Access specified memory space instead default memory space of current target. For Arm DAP targets, address spaces DPR, APR and AP<n> can be used to access DP registers, AP registers, and MEM-AP addresses respectively. For backwards compatibility, the -arm-dap and -arm-ap options can be used as shorthand for "-address-space APR" and "-address-space AP<n>" respectively. The APR address range is 0x0 - 0xfffc, where the higher eight bits select an AP and the lower eight bits are the register address for that AP.
-unaligned-access The memory address is not aligned to the access size before performing a read operation. Support for unaligned accesses is target architecture dependent. If this option is not specified, addresses are automatically aligned to access size.


  • Select an APU target to access ARM DAP and MEM-AP address space.


Memory addresses and data in requested format, if successful. Error string, if the target memory cannot be read.


mrd 0x0

Read a word at 0x0.

mrd 0x0 10

Read 10 words at 0x0.

mrd -value 0x0 10

Read 10 words at 0x0 and return a Tcl list of values.

mrd -size b 0x1 3

Read three bytes at address 0x1.

mrd -size h 0x2 2

Read two half-words at address 0x2.

mrd -bin -file mem.bin 0 100

Read 100 words at address 0x0 and write the binary data to mem.bin.

mrd -address-space APR 0x100

Read APB-AP CSW on Zynq. The higher eight bits (0x1) select the APB-AP and the lower eight bits (0x0) are the address of CSW.

mrd -address-space APR 0x04

Read AHB-AP TAR on Zynq. The higher eight bits (0x0) select the AHB-AP and the lower eight bits (0x4) are the address of TAR.

mrd -address-space AP1 0x80090088

Read address 0x80090088 on DAP APB-AP. AP 1 selects the APB-AP. 0x80090088 on APB-AP corresponds to DBGDSCR of Cortex-A9#0, on Zynq.

mrd -address-space AP0 0xe000d000

Read address 0xe000d000 on DAP AHB-AP. AP 0 selects the AHB-AP. 0xe000d000 on AHB-AP corresponds to QSPI device on Zynq.