z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 188

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

ESPI Signals
PS022006-0207
Master-In/Slave-Out
Master-Out/Slave-In
Serial Clock
Slave Select
The four ESPI signals are:
•
•
•
•
The following paragraphs describe these signals in both MASTER and SLAVE modes.
The appropriate GPIO pins must be configured using the GPIO alternate function
registers.
The MISO pin is configured as an input in a master device and as an output in a slave
device. Data is transferred to most significant bit first. The MISO pin of a slave device is
placed in a high-impedance state if the slave is not selected. When the ESPI is not enabled,
this signal is in a high-impedance state. The direction of this pin is controlled by the
bit of the ESPI control register.
The MOSI pin is configured as an output in a master device and as an input in a slave
device. Data is transferred to most significant bit first. When the ESPI is not enabled, this
signal is in a high-impedance state. The direction of this pin is controlled by the
of the ESPI control register.
The SCK synchronizes data movement both in and out of the shift register via the MOSI
and MISO pins. In MASTER mode (
serial clock and drives it out via its SCK pin to the slave devices. In SLAVE mode, the
SCK pin is an input. Slave devices ignore the SCK signal unless their SS pin is asserted.
The master and slave are each capable of exchanging a character of data during a sequence
of NUMBITS clock cycles (see NUMBITS field in the
In both master and slave ESPI devices, data is shifted on one edge of the SCK and is
sampled on the opposite edge where data is stable. SCK phase and polarity is determined
by the
The SS signal is a bidirectional framing signal with several modes of operation to support
SPI and other synchronous serial interface protocols. The SLAVE SELECT mode is
selected by the SSMD field of the ESPI mode register. The direction of the SS signal is
Master-In/Slave-Out (MISO)
Master-Out/Slave-In (MOSI)
Serial clock (SCK)
Slave select (SS)
Phase
and
Clkpol
P R E L I M I N A R Y
bits in the
MMEN = 1
ESPI Control Register
), the ESPI’s baud rate generator creates the
Enhanced Serial Peripheral Interface
ESPI Mode Register
on page 190.
Product Specification
ZNEO
™
on page 192).
Z16F Series
MMEN
MMEN
bit
174