MC68332GVEH25 Freescale Semiconductor, MC68332GVEH25 Datasheet - Page 64

• Manufacturer Part Number: MC68332GVEH25
• Description: IC MCU 32BIT 25MHZ 132-PQFP
• Manufacturer: Freescale Semiconductor
• Series: M683xxr

Specifications of MC68332GVEH25

• Core Processor: CPU32
• Core Size: 32-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, SCI, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 15
• Program Memory Type: ROMless
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 132-QFP
• Processor Series: M683xx
• Core: CPU32
• Data Bus Width: 32 bit
• Controller Family/series: 68K
• No. Of I/o's: 15
• Ram Memory Size: 2KB
• Cpu Speed: 25MHz
• No. Of Timers: 1
• Embedded Interface Type: QSPI, SCI, UART
• Digital Ic Case Style: PQFP
• Rohs Compliant: Yes
• Data Ram Size: 2 KB
• Interface Type: QSPI, SCI, UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 15
• Number Of Timers: 16
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4.5.2.1 Read Cycle
4-24
To initiate a transfer, the MCU asserts an address and the SIZ[1:0] signals. The SIZ
signals and ADDR0 are externally decoded to select the active portion of the data bus
(refer to 4.4.2 Dynamic Bus Sizing). When AS, DS, and R/W are valid, a peripheral
device either places data on the bus (read cycle) or latches data from the bus (write
cycle), then asserts a DSACK[1:0] combination that indicates port size.
The DSACK[1:0] signals can be asserted before the data from a peripheral device is
valid on a read cycle. To ensure valid data is latched into the MCU, a maximum period
between DSACK assertion and DS assertion is specified.
There is no specified maximum for the period between the assertion of AS and
DSACK. Although the MCU can transfer data in a minimum of three clock cycles when
the cycle is terminated with DSACK, the MCU inserts wait cycles in clock period incre-
ments until either DSACK signal goes low.
If no peripheral responds to an access, or if an access is invalid, external logic should
assert the BERR or HALT signals to abort the bus cycle (when BERR and HALT are
asserted simultaneously, the CPU32 acts as though only BERR is asserted). If bus ter-
mination signals are not asserted within a specified period, the bus monitor terminates
the cycle.
During a read cycle, the MCU transfers data from an external memory or peripheral
device. If the instruction specifies a long-word or word operation, the MCU attempts to
read two bytes at once. For a byte operation, the MCU reads one byte. The portion of
the data bus from which each byte is read depends on operand size, peripheral ad-
dress, and peripheral port size. Figure 4-9 is a flowchart of a word read cycle. Refer
to 4.4.2 Dynamic Bus Sizing, 4.4.4 Misaligned Operands, and the SIM Reference
Manual (SIMRM/AD) for more information.
The SIM bus monitor asserts BERR when response time exceeds a
predetermined limit. Bus monitor period is determined by the BMT
field in SYPCR. The bus monitor cannot be disabled; maximum mon-
itor period is 64 system clock cycles.
Freescale Semiconductor, Inc.
For More Information On This Product,
SYSTEM INTEGRATION MODULE
Go to: www.freescale.com
NOTE
USER’S MANUAL
MC68332