MC68EN360AI25VL Freescale, MC68EN360AI25VL Datasheet - Page 207

• Manufacturer Part Number: MC68EN360AI25VL
• Manufacturer: Freescale

Specifications of MC68EN360AI25VL

• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 25MHz
• Instruction Set Architecture: RISC
• Operating Supply Voltage (max): 3.3V
• Operating Supply Voltage (min): 2.7V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 240
• Package Type: FQFP
• Lead Free Status / RoHS Status: Compliant

5.6.2.7.1 CPU Serial Logic. CPU32+ serial logic, shown in the left-hand portion of Figure
5-22, consists of transmit and receive shift registers and of control logic that includes syn-
chronization, serial clock generation circuitry, and a received bit counter.
Both DSCLK and DSI are synchronized to on-chip clocks, thereby minimizing the chance of
propagating metastable states into the serial state machine. Data is sampled during the high
phase of CLKOUT. At the falling edge of CLKOUT, the sampled value is made available to
internal logic. If there is no synchronization between CPU32+ and development system
hardware, the minimum hold time on DSI with respect to DSCLK is one full period of CLK-
OUT.
The serial state machine begins a sequence of events based on the rising edge of the syn-
chronized DSCLK (see Figure 5-23). Synchronized serial data is transferred to the input shift
register, and the received bit counter is decremented. One-half clock period later, the output
shift register is updated, bringing the next output bit to the DSO signal. DSO changes rela-
tive to the rising edge of DSCLK and does not necessarily remain stable until the falling edge
of DSCLK.
One clock period after the synchronized DSCLK has been seen internally, the updated
counter value is checked. If the counter has reached zero, the receive data latch is updated
from the input shift register. At this same time, the output shift register is reloaded with the
MICROSEQUENCER
SYNCHRONIZE
EXECUTION
STATUS
UNIT
Figure 5-22. Debug Serial I/O Block Diagram
Freescale Semiconductor, Inc.
For More Information On This Product,
RCV DATA LATCH
PARALLEL OUT
REGISTER BUS
PARALLEL IN
INSTRUCTION
SERIAL OUT
SERIAL IN
MC68360 USER’S MANUAL
Go to: www.freescale.com
CPU
16
16
CONTROL
LOGIC
DSCLK
DSO
DSI
STATUS
0
DEVELOPMENT SYSTEM
COMMAND LATCH
PARALLEL OUT
RESULT LATCH
CONTROL
PARALLEL IN
SERIAL OUT
LOGIC
SERIAL IN
DATA
DATA
16
16
SERIAL
CLOCK
CPU32+