MC68HC16Z1CFC16 Freescale Semiconductor, MC68HC16Z1CFC16 Datasheet - Page 169

• Manufacturer Part Number: MC68HC16Z1CFC16
• Description: IC MPU 1K RAM 16MHZ 132-PQFP
• Manufacturer: Freescale Semiconductor
• Series: HC16r

Specifications of MC68HC16Z1CFC16

• Core Processor: CPU16
• Core Size: 16-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: ROMless
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 132-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -

5.9.1 Chip-Select Registers
M68HC16 Z SERIES
USER’S MANUAL
Chip-select assertion can be synchronized with bus control signals to provide output
enable, read/write strobe, or interrupt acknowledge signals. Logic can also generate
DSACK and AVEC signals internally. A single DSACK generator is shared by all chip-
selects. Each signal can also be synchronized with the ECLK signal available on
ADDR23.
When a memory access occurs, chip-select logic compares address space type, ad-
dress, type of access, transfer size, and interrupt priority (in the case of interrupt ac-
knowledge) to parameters stored in chip-select registers. If all parameters match, the
appropriate chip-select signal is asserted. Select signals are active low. If a chip-select
function is given the same address as a microcontroller module or an internal memory
array, an access to that address goes to the module or array, and the chip-select sig-
nal is not asserted. The external address and data buses do not reflect the internal ac-
cess.
All chip-select circuits are configured for operation out of reset. However, all chip-se-
lect signals except CSBOOT are disabled, and cannot be asserted until the BYTE[1:0]
field in the corresponding option register is programmed to a non-zero value to select
a transfer size. The chip-select option register must not be written until a base address
has been written to a proper base address register. Alternate functions for chip-select
pins are enabled if appropriate data bus pins are held low at the release of RESET.
Refer to
functional diagram of a single chip-select circuit.
Each chip-select pin can have one or more functions. Chip-select pin assignment reg-
isters CSPAR[1:0] determine functions of the pins. Pin assignment registers also de-
termine port size (8- or 16-bit) for dynamic bus allocation. A pin data register (PORTC)
latches data for chip-select pins that are used for discrete output.
DSACK
BUS CONTROL
AVEC
5.7.3.1 Data Bus Mode Selection
ADDRESS
INTERNAL
SIGNALS
Figure 5-22 Chip-Select Circuit Block Diagram
Freescale Semiconductor, Inc.
GENERATOR
For More Information On This Product,
AVEC
BASE ADDRESS REGISTER
ADDRESS COMPARATOR
SYSTEM INTEGRATION MODULE
OPTION COMPARE
OPTION REGISTER
Go to: www.freescale.com
GENERATOR
DSACK
for more information.
ASSIGNMENT
REGISTER
PIN
CONTROL
TIMING
AND
REGISTER
DATA
PIN
Figure 5-22
PIN
CHIP SEL BLOCK
is a
5-63