M68HC16 Z SERIES
CENTRAL PROCESSING UNIT
USER’S MANUAL
4-45
4.15 Recommended BDM Connection
In order to use BDM development tools when an MCU is installed in a system,
Freescale
recommends that appropriate signal lines be routed to a male Berg connector or
double-row header installed on the circuit board with the MCU. Refer to
Figure 4-8 BDM Connector Pinout
4.16 Digital Signal Processing
The CPU16 performs low-frequency digital signal processing (DSP) algorithms in real
time. The most common DSP operation in embedded control applications is filtering,
but the CPU16 can perform several other useful DSP functions. These include auto-
correlation (detecting a periodic signal in the presence of noise), cross-correlation (de-
termining the presence of a defined periodic signal), and closed-loop control routines
(selective filtration in a feedback path).
Although derivation of DSP algorithms is often a complex mathematical task, the algo-
rithms themselves typically consist of a series of multiply and accumulate (MAC)
operations. The CPU16 contains a dedicated set of registers that perform MAC oper-
ations. As a group, these registers are called the MAC unit.
DSP operations generally require a large number of MAC iterations. The CPU16 in-
struction set includes instructions that perform MAC setup and repetitive MAC opera-
tions. Other instructions, such as 32-bit load and store instructions, can also be used
in DSP routines.
Many DSP algorithms require extensive data address manipulation. To increase
throughput, the CPU16 performs effective address calculations and data prefetches
during MAC operations. In addition, the MAC unit provides modulo addressing to im-
plement circular DSP buffers efficiently.
Refer to the
CPU16 Reference Manual (CPU16RM/AD) for detailed information con-
cerning the MAC unit and execution of DSP instructions.
DS
GND
GND
RESET
VDD
BERR
BKPT/DSCLK
FREEZE
IPIPE1/DSI
IPIPE0/DSO
1
3
5
7
9
2
4
6
8
10
BDM CONN
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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