PC312XDP512F0CFVR datasheet(576/1348 Pages) FREESCALE

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Chapter 15 Background Debug Module (S12XBDMV2)

MC9S12XDP512 Data Sheet, Rev. 2.21

576

Freescale Semiconductor

15.3.2.2

BDM CCR LOW Holding Register (BDMCCRL)

Figure 15-4. BDM CCR LOW Holding Register (BDMCCRL)

Read: All modes through BDM operation when not secured

Write: All modes through BDM operation when not secured

NOTE

When BDM is made active, the CPU stores the content of its CCRL register

in the BDMCCRL register. However, out of special single-chip reset, the

BDMCCRL is set to 0xD8 and not 0xD0 which is the reset value of the

CCRL register in this CPU mode. Out of reset in all other modes the

BDMCCRL register is read zero.

When entering background debug mode, the BDM CCR LOW holding register is used to save the low byte

of the condition code register of the user’s program. It is also used for temporary storage in the standard

BDM ﬁrmware mode. The BDM CCR LOW holding register can be written to modify the CCR value.

Table 15-3. BDM Clock Sources

PLLSEL

CLKSW

BDMCLK

Bus clock dependent on oscillator

Alternate clock (refer to the device speciﬁcation to determine the alternate clock source)

Bus clock dependent on the PLL

CCR7

CCR6

CCR5

CCR4

CCR3

CCR2

CCR1

CCR0

Reset

Special Single-Chip Mode

All Other Modes

PC312XDP512F0CFVR Datasheet(PDF) 576 Page - Freescale Semiconductor, Inc