Development Support
MPC561/MPC563 Reference Manual, Rev. 1.2
23-16
Freescale Semiconductor
23.2.2.1
Load/Store Support
There are two load/store address comparators E, and F. Each compares the 32 address bits and the cycle’s
attributes (read/write). The two least-significant bits are masked (ignored) whenever a word is accessed
and the least-significant bit is masked whenever a half-word is accessed. (For more information refer to
Section 23.2.1.2, “Byte and Half-Word Working Modes
”). Each comparator generates two output signals:
equal and less than. These signals are used to generate one of the following four events (one from each
comparator): equal, not equal, greater than, less than.
There are two load/store data comparators (comparators G,H) each is 32 bits wide and can be programmed
to treat numbers either as signed values or as unsigned values. Each data comparator operates as four
independent byte comparators. Each byte comparator has a mask bit and generates two output signals:
equal and less than, if the mask bit is not set. Therefore, each 32 bit comparator has eight output signals.
These signals are used to generate the “equal and less than” signals according to the compare size
programmed (byte, half-word, word). When operating in byte mode all signals are significant, when
operating in half-word mode only four signals from each 32 bit comparator are significant. When operating
in word mode only two signals from each 32 bit comparator are significant.
From the new “equal and less than” signals and according to the compare type programmed one of the
following four match events are generated: equal, not equal, greater than, less than. Therefore, from the
two 32-bit comparators eight match indications are generated: Gmatch[0:3], Hmatch[0:3].
According to the lower bits of the address and the size of the cycle, only match indications that were
detected on bytes that have valid information are validated, the rest are negated. Note that if the cycle
executed has a smaller size than the compare size (e.g., a byte access when the compare size is word or
half-word) no match indication will be asserted.
Using the match indication signals four load/store data events are generated in the following way.
The four load/store data events together with the match events of the load/store address comparators and
the instruction watchpoints are used to generate the load/store watchpoints and breakpoint according to the
programming.
Table 23-7. Load/Store Data Events
Event Name
Event Function
1
1
‘&’ denotes a logical AND, ‘|’ denotes a logical OR
G
(Gmatch0 | Gmatch1 | Gmatch2 | Gmatch3)
H
(Hmatch0 | Hmatch1 | Hmatch2 | Hmatch3)
(G&H)
((Gmatch0 & Hmatch0) | (Gmatch1 & Hmatch1) | (Gmatch2 & Hmatch2) | (Gmatch3 & Hmatch3))
(G | H)
((Gmatch0 | Hmatch0) | (Gmatch1 | Hmatch1) | (Gmatch2 | Hmatch2) | (Gmatch3 | Hmatch3))
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...
