
Debug Module
Freescale Semiconductor
36-35
The BDM programming model supports reads and writes to A7 and OTHER_A7 directly. It is the
responsibility of the external development system to determine the mapping of A7 and OTHER_A7 to the
two program-visible definitions (supervisor and user stack pointers), based on the SR[S] bit.
36.4.1.5.12
BDM Accesses of the EMAC Registers
The presence of rounding logic in the output datapath of the EMAC requires special care for
BDM-initiated reads and writes of its programming model. In particular, any result rounding modes must
be disabled during the read/write process so the exact bit-wise EMAC register contents are accessed.
For example, a BDM read of an accumulator (ACC
x
) must be preceded by two commands accessing the
MAC status register, as shown in the following sequence:
BdmReadACCx (
rcreg
macsr;
// read current macsr contents and save
wcreg
#0,macsr;
// disable all rounding modes
rcreg
ACCx;
// read the desired accumulator
wcreg
#saved_data,macsr;// restore the original macsr
)
Likewise, to write an accumulator register, the following BDM sequence is needed:
BdmWriteACCx (
rcreg
macsr;
// read current macsr contents and save
wcreg
#0,macsr;
// disable all rounding modes
wcreg
#data,ACCx;
// write the desired accumulator
wcreg
#saved_data,macsr;// restore the original macsr
)
Additionally, writes to the accumulator extension registers must be performed after the corresponding
accumulators are updated because a write to any accumulator alters the corresponding extension register
contents.
For more information on saving and restoring the complete EMAC programming model, see
Section 4.3.1.2, “Saving and Restoring the EMAC Programming Model.”
36.4.1.5.13
Write Control Register (
WCREG
)
The operand (longword) data is written to the specified control register. The write alters all 32 register bits.
See the RCREG instruction description for the Rc encoding and for additional notes on writes to the A7
stack pointers and the EMAC programming model.
Command/Result Formats:
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Command
0x2
0x8
0x8
0x0
0x0
0x0
0x0
0x0
0x0
Rc
Result
D[31:16]
D[15:0]
Figure 36-37.
WCREG
Command/Result Formats
MCF5329 Reference Manual, Rev 3
Summary of Contents for MCF5329
Page 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...