x+3
x+2
x+1
x
4c.v_wxyz
next
next
next
orig_1bit
400v_wxyz
400v_wxyz
next
next
next
rdata + 1bit
rdata
4c.v_wxyz
rdata + 1bit
CYCLE RULER
hclk
BME AHB Input Bus
mx_haddr
mx_hattr
mx_hwrite
mx_hwdata
mx_hrdata
mx_hready
BME AHB Output Bus
sx_haddr
sx_hattr
sx_hwrite
sx_hwdata
sx_hrdata
sx_hready
BME Datapath
control_state_dp1
control_state_dp2
reg_addr_data_dp
Figure 42-7. Decorated load: load-and-set 1-bit field insert timing diagram
Decorated load-and-{set, clear} 1-bit operations follow the execution template shown in
the above figure: a 2-cycle read-modify-write operation:
1. Cycle x, first AHB address phase: Read from input bus is translated into a read
operation on the output bus with the actual memory address (with the decoration
removed) and then captured in a register
2. Cycle x+1, second AHB address phase: Write access with the registered (but actual)
memory address is output
3. Cycle x+1, first AHB data phase: The "original" 1-bit memory read data is captured
in a register, while the 1-bit field is set or clear based on the function defined by the
decoration with the modified data captured in a register; the input bus cycle is stalled
4. Cycle x+2, second AHB data phase: The selected original 1-bit is right-justified,
zero-filled and then driven onto the input read data bus, while the registered write
data is sourced onto the output write data bus
Functional description
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
842
Freescale Semiconductor, Inc.
