Functional Description

MC13192 Technical Data, Rev. 3.3

Freescale Semiconductor

11

6

Functional Description

6.1

MC13192 Operational Modes

The MC13192 has a number of operational modes that allow for low-current operation. Transition from

the Off to Idle mode occurs when RST is negated. Once in Idle, the SPI is active and is used to control the

IC. Transition to Hibernate and Doze modes is enabled via the SPI. These modes are summarized, along

with the transition times, in Table 7. Current drain in the various modes is listed in Table 3, DC Electrical

Characteristics.

6.2

Serial Peripheral Interface (SPI)

The host microcontroller directs the MC13192, checks its status, and reads/writes data to the device

through the 4-wire SPI port. The transceiver operates as a SPI slave device only. A transaction between

the host and the MC13192 occurs as multiple 8-bit bursts on the SPI. The SPI signals are:

1. Chip Enable (CE) - A transaction on the SPI port is framed by the active low CE input signal. A

transaction is a minimum of 3 SPI bursts and can extend to a greater number of bursts.

2. SPI Clock (SPICLK) - The host drives the SPICLK input to the MC13192. Data is clocked into the

master or slave on the leading (rising) edge of the return-to-zero SPICLK and data out changes

state on the trailing (falling) edge of SPICLK.

NOTE

For Freescale microcontrollers, the SPI clock format is the clock phase

control bit CPHA = 0 and the clock polarity control bit CPOL = 0.

3. Master Out/Slave In (MOSI) - Incoming data from the host is presented on the MOSI input.

4. Master In/Slave Out (MISO) - The MC13192 presents data to the master on the MISO output.

A typical interconnection to a microcontroller is shown in Figure 7.

Table 7. MC13192 Mode Definitions and Transition Times

Mode

Definition

Transition Time

To or From Idle

Off

All IC functions Off, Leakage only. RST asserted. Digital outputs are tri-stated including

IRQ

10 - 25 ms to Idle

Hibernate

Crystal Reference Oscillator Off. (SPI not functional.) IC Responds to ATTN. Data is

retained.

7 - 20 ms to Idle

Doze

Crystal Reference Oscillator On but CLKO output available only if Register 7, Bit 9 = 1

for frequencies of 1 MHz or less. (SPI not functional.) Responds to ATTN and can be

programmed to enter Idle Mode through an internal timer comparator.

(300 + 1/CLKO) µs

to Idle

Idle

Crystal Reference Oscillator On with CLKO output available. SPI active.

Receive

Crystal Reference Oscillator On. Receiver On.

144 µs from Idle

Transmit

Crystal Reference Oscillator On. Transmitter On.

144 µs from Idle