MC908AZ32ACFU Freescale Semiconductor, MC908AZ32ACFU Datasheet - Page 145

• Manufacturer Part Number: MC908AZ32ACFU
• Description: IC MCU 32K FLASH 8.4MHZ 64-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908AZ32ACFU

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: CAN, SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 40
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 15x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

16.4.2.4 Idle Characters
An idle character contains all logic 1s and has no start, stop, or parity bit. Idle character length depends
on the M bit in SCC1. The preamble is a synchronizing idle character that begins every transmission.
If the TE bit is cleared during a transmission, the TxD pin becomes idle after completion of the
transmission in progress. Clearing and then setting the TE bit during a transmission queues an idle
character to be sent after the character currently being transmitted.
16.4.2.5 Inversion of Transmitted Output
The transmit inversion bit (TXINV) in SCI control register 1 (SCC1) reverses the polarity of transmitted
data. All transmitted values, including idle, break, start, and stop bits, are inverted when TXINV is at logic
1. (See 16.8.1 SCI Control Register 1.)
16.4.2.6 Transmitter Interrupts
The following conditions can generate CPU interrupt requests from the SCI transmitter:
16.4.3 Receiver
Figure 16-6
Freescale Semiconductor
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SCI transmitter empty (SCTE) — The SCTE bit in SCS1 indicates that the SCDR has transferred
a character to the transmit shift register. SCTE can generate a transmitter CPU interrupt request.
Setting the SCI transmit interrupt enable bit, SCTIE, in SCC2 enables the SCTE bit to generate
transmitter CPU interrupt requests.
Transmission complete (TC) — The TC bit in SCS1 indicates that the transmit shift register and the
SCDR are empty and that no break or idle character has been generated. The transmission
complete interrupt enable bit, TCIE, in SCC2 enables the TC bit to generate transmitter CPU
interrupt requests.
shows the structure of the SCI receiver.
When a break sequence is followed immediately by an idle character, this
SCI design exhibits a condition in which the break character length is
reduced by one half bit time. In this instance, the break sequence will
consist of a valid start bit, eight or nine data bits (as defined by the M bit in
SCC1) of logic 0 and one half data bit length of logic 0 in the stop bit position
followed immediately by the idle character. To ensure a break character of
the proper length is transmitted, always queue up a byte of data to be
transmitted while the final break sequence is in progress.
When queueing an idle character, return the TE bit to logic 1 before the stop
bit of the current character shifts out to the TxD pin. Setting TE after the stop
bit appears on TxD causes data previously written to the SCDR to be lost.
A good time to toggle the TE bit for a queued idle character is when the
SCTE bit becomes set and just before writing the next byte to the SCDR.
MC68HC908AZ32A Data Sheet, Rev. 2
NOTE
NOTE
Functional Description
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