MC68340AG16E Freescale Semiconductor, MC68340AG16E Datasheet - Page 392

• Manufacturer Part Number: MC68340AG16E
• Description: IC MPU 32BIT 16MHZ 144-LQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68340AG16E

• Processor Type: M683xx 32-Bit
• Speed: 16MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 144-LQFP
• Controller Family/series: 68K
• Core Size: 32 Bit
• No. Of I/o's: 16
• Cpu Speed: 16MHz
• No. Of Timers: 2
• Embedded Interface Type: UART
• Digital Ic Case Style: LQFP
• Rohs Compliant: Yes
• Processor Series: M683xx
• Core: CPU32
• Maximum Clock Frequency: 16 MHz
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Details

10.2 MEMORY INTERFACE INFORMATION
The following paragraphs contain information on using an 8-bit boot ROM, performing
access time calculations, calculating frequency-adjusted outputs, and interfacing an 8-bit
device to 16-bit memory using the DMA channel single-address mode.
10.2.1 Using an 8-Bit Boot ROM
Upon power-up, the MC68340 uses CS0 to begin operation. CS0 is a three-wait-state, 16-
bit chip select, until otherwise programmed. If an 8-bit ROM is desired, external circuitry
can be added to return an 8-bit DSACK in two wait states (see Figure 10-8).
The `393 is a falling edge-triggered counter; thus, CS0 is stable during the time in which it
is being clocked. CS0 acts as the asynchronous reset—i.e., when it is asserted, the `393
is allowed to count. The falling edge of S2 provides the first counting edge. Q1 does not
transition on this falling edge, but transitions to a logic one on the subsequent edge.
DSACK0 is Q1 inverted; thus, on the next falling edge, DSACK0 is seen as asserted,
indicating an 8-bit port. When CS0 is negated, Q1 is again held in reset and DSACK0 is
negated. The timing diagram in Figure 10-9 illustrates this operation.
MOTOROLA
Figure 10-8. External Circuitry for 8-Bit Boot ROM
Freescale Semiconductor, Inc.
For More Information On This Product,
MC68340
CLKOUT
Figure 10-7. Serial Interface
RxDx
TxDx
CS0
X2
X1
MC68340 USER’S MANUAL
Go to: www.freescale.com
10
10
F
F
3.6864 MHz
C1+
C1-
CP
V
GND
MR
MC145407
SS
T
15 pF
5 pF
R
'393
C2+
C1-
C2+
C2-
Rx1
Tx1
Q0
Q3
V
Q1
Q2
CC
10
10
F
F
DSACK0
10-5