MC68331MEH16 Freescale Semiconductor, MC68331MEH16 Datasheet - Page 29

• Manufacturer Part Number: MC68331MEH16
• Description: IC MCU 32BIT 16MHZ 132-PQFP
• Manufacturer: Freescale Semiconductor
• Series: M683xxr

Specifications of MC68331MEH16

• Core Processor: CPU32
• Core Size: 32-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, SCI, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Type: ROMless
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 132-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Ram Size: -
• Program Memory Size: -
• Data Converters: -

3.5.1 Chip-Select Registers
MC68331TS/D
The following table lists allocation of chip-selects and discrete outputs on the pins of the MCU.
Pin assignment registers CSPAR0 and CSPAR1 determine functions of chip-select pins. These regis-
ters also determine port size (8- or 16-bit) for dynamic bus allocation.
A pin data register (PORTC) latches discrete output data.
Blocks of addresses are assigned to each chip-select function. Block sizes of 2 Kbytes to 1 Mbyte can
be selected by writing values to the appropriate base address register (CSBAR). Address blocks for
separate chip-select functions can overlap.
Chip-select option registers (CSORBT and CSOR[10:0]) determine timing of and conditions for asser-
tion of chip-select signals. Eight parameters, including operating mode, access size, synchronization,
and wait state insertion can be specified.
Initialization code often resides in a peripheral memory device controlled by the chip-select circuits. A
set of special chip-select functions and registers (CSORBT, CSBARBT) is provided to support bootstrap
operation.
DSACK
BUS CONTROL
AVEC
ADDRESS
INTERNAL
SIGNALS
Freescale Semiconductor, Inc.
GENERATOR
Figure 9 Chip-Select Circuit Block Diagram
CSBOOT
For More Information On This Product,
ADDR19
ADDR20
ADDR21
ADDR22
ADDR23
BGACK
AVEC
FC0
FC1
FC2
Pin
BR
BG
BASE ADDRESS REGISTER
ADDRESS COMPARATOR
OPTION COMPARE
OPTION REGISTER
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GENERATOR
DSACK
Chip Select
CSBOOT
CS10
CS0
CS1
CS2
CS3
CS4
CS5
CS6
CS7
CS8
CS9
ASSIGNMENT
REGISTER
Discrete Outputs
PIN
ECLK
CONTROL
PC0
PC1
PC2
PC3
PC4
PC5
PC6
TIMING
—
—
—
—
AND
REGISTER
DATA
PIN
PIN
CHIP SEL BLOCK
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