MC68376BGMAB20 Freescale Semiconductor, MC68376BGMAB20 Datasheet - Page 138

• Manufacturer Part Number: MC68376BGMAB20
• Description: IC MCU 32BIT 8K ROM 160-QFP
• Manufacturer: Freescale Semiconductor
• Series: M683xxr

Specifications of MC68376BGMAB20

• Core Processor: CPU32
• Core Size: 32-Bit
• Speed: 20MHz
• Connectivity: CAN, EBI/EMI, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Type: ROMless
• Ram Size: 7.5K x 8
• Voltage - Supply (vcc/vdd): 4.75 V ~ 5.25 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 160-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

5.9.1.4 Port C Data Register
5.9.2 Chip-Select Operation
5-60
MOTOROLA
The STRB bit controls the timing of a chip-select assertion in asynchronous mode. Se-
lecting address strobe causes a chip-select signal to be asserted synchronized with
the address strobe. Selecting data strobe causes a chip-select signal to be asserted
synchronized with the data strobe. This bit has no effect in synchronous mode.
DSACK[3:0] specifies the source of DSACK in asynchronous mode. It also allows the
user to optimize bus speed in a particular application by controlling the number of wait
states that are inserted.
SPACE[1:0] determines the address space in which a chip-select is asserted. An ac-
cess must have the space type represented by the SPACE[1:0] encoding in order for
a chip-select signal to be asserted.
IPL[2:0] contains an interrupt priority mask that is used when chip-select logic is set to
trigger on external interrupt acknowledge cycles. When SPACE[1:0] is set to %00
(CPU space), interrupt priority (ADDR[3:1]) is compared to the IPL field. If the values
are the same, and other option register constraints are satisfied, a chip-select signal
is asserted. This field only affects the response of chip-selects and does not affect in-
terrupt recognition by the CPU. Encoding %000 in the IPL field causes a chip-select
signal to be asserted regardless of interrupt acknowledge cycle priority, provided all
other constraints are met.
The AVEC bit is used to make a chip-select respond to an interrupt acknowledge
cycle. If the AVEC bit is set, an autovector will be selected for the particular external
interrupt being serviced. If AVEC is zero, the interrupt acknowledge cycle will be ter-
minated with DSACK, and an external vector number must be supplied by an external
device.
The port C data register latches data for PORTC pins programmed as discrete out-
puts. When a pin is assigned as a discrete output, the value in this register appears at
the output. PC[6:0] correspond to CS[9:3]. Bit 7 is not used. Writing to this bit has no
effect, and it always reads zero.
When the MCU makes an access, enabled chip-select circuits compare the following
items:
• Function codes to SPACE fields, and to the IPL field if the SPACE field encoding
• Appropriate address bus bits to base address fields.
• Read/write status to R/W fields.
• ADDR0 and/or SIZ[1:0] bits to BYTE fields (16-bit ports only).
• Priority of the interrupt being acknowledged (ADDR[3:1]) to IPL fields (when the
is not for CPU space.
access is an interrupt acknowledge cycle).
The external DSACK pins are always active.
SYSTEM INTEGRATION MODULE
NOTE
USER’S MANUAL
MC68336/376