Bdc Serial Interface - NXP Semiconductors MC9S12ZVH64 Reference Manual

Chapter 5 Background Debug Controller (S12ZBDCV2)
5.4.5.2.2 READ_SAME Effects Of Variable Access Size
READ_SAME uses the unadjusted address given in the previous READ_MEM command as a base
address for subsequent READ_SAME commands. When the READ_MEM and READ_SAME size
parameters differ then READ_SAME uses the original base address buts aligns 32-bit and 16-bit accesses,
where those accesses would otherwise cross the aligned 4-byte boundary.
examples of this.
d
Table 5-12. Consecutive READ_SAME Accesses With Variable Size
Row Command
1 READ_MEM.32
2 READ_SAME.32
3 READ_SAME.16
4 READ_SAME.08
5 READ_MEM.08
6 READ_SAME.08
7 READ_SAME.16
8 READ_SAME.32
9 READ_MEM.08
10 READ_SAME.08
11 READ_SAME.16
12 READ_SAME.32
13 READ_MEM.08
14 READ_SAME.08
15 READ_SAME.16
16 READ_SAME.32
17 READ_MEM.16
18 READ_SAME.08
19 READ_SAME.16
20 READ_SAME.32
21 READ_MEM.16
22 READ_SAME.08
23 READ_SAME.16
24 READ_SAME.32
5.4.6

BDC Serial Interface

The BDC communicates with external devices serially via the BKGD pin. During reset, this pin is a mode
select input which selects between normal and special modes of operation. After reset, this pin becomes
the dedicated serial interface pin for the BDC.
The BDC serial interface uses an internal clock source, selected by the CLKSW bit in the BDCCSR
register. This clock is referred to as the target clock in the following explanation.
166
Base Address 00
0x004003 Accessed
— Accessed
—
—
0x004000 Accessed
— Accessed
— Accessed
— Accessed
0x004002
—
—
— Accessed
0x004003
—
—
— Accessed
0x004001
—
—
— Accessed
0x004003
—
—
— Accessed
S12ZVH Family Reference Manual, Rev. 1.05
Table 5-12 shows some
01 10
Accessed Accessed
Accessed Accessed
Accessed
Accessed
Accessed Accessed
Accessed
Accessed
Accessed
Accessed Accessed
Accessed
Accessed Accessed
Accessed Accessed
Accessed
Accessed Accessed
Accessed Accessed
Accessed
Accessed
Accessed Accessed
Freescale Semiconductor
11
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed
Accessed