mrd - 2021.2 English

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

Document ID
Release Date
2021.2 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 will be aligned to access-size before reading memory, if '-unaligned-access' option is not used. For targets which do not support double-word access, debugger uses 2 word accesses. If number of data values to be read is more than 1, then debugger selects appropriate access size. For example, 1. mrd -size b 0x0 4 Debugger accesses one word from the memory, displays 4 bytes. 2. mrd -size b 0x0 3 Debugger accesses one half-word and one byte from the memory, displays 3 bytes. 3. mrd 0x0 3 Debugger accesses 3 words from the memory and displays 3 words.
-value Return a Tcl list of values, instead of displaying the result on 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 -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 8 bits select an AP and lower 8 bits are the register address for that AP.
-unaligned-access Memory address is not aligned to 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 a 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 3 bytes at address 0x1.

mrd -size h 0x2 2

Read 2 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 8 bits (0x1) select the APB-AP and lower 8 bits (0x0) is the address of CSW.

mrd -address-space APR 0x04

Read AHB-AP TAR on Zynq. The higher 8 bits (0x0) select the AHB-AP and lower 8 bits (0x4) is the address of TAR.

mrd -address-space AP1 0x80090088

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

mrd -address-space AP0 0xe000d000

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