z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 202

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

ESPI Control Register Definitions
PS022006-0207
ESPI Baud Rate Generator
ESPI Data Register
SPI BRG Interrupt Interval (s)
TUND, COL, ABT, ROVR —See the Status Register for description of these bits.
RSS—Value of SS associated with last byte written (useful in I2S mode to distinquish
left/right channel data).
In ESPI MASTER mode, the BRG creates a lower frequency serial clock (SCK) for data
transmission synchronization between the Master and the external Slave. The input to the
BRG is the system clock. The ESPI Baud Rate High and Low Byte registers combine to
form a 16-bit reload value, BRG[15:0], for the ESPI BRG. The ESPI baud rate is
calculated using the following equation:
Minimum baud rate is obtained by setting BRG[15:0] to 0000H for a clock divisor value
of (2 x 65536 = 131072).
When the ESPI is disabled, the BRG functions as a basic 16-bit timer with interrupt on
timeout. Follow the steps below to configure the BRG as a timer with interrupt on timeout:
1. Disable the ESPI by clearing the ESPIEN1,0 bits in the ESPI Control register.
2. Load the appropriate 16-bit count value into the ESPI Baud Rate High and Low Byte
3. Enable the BRG timer function and associated interrupt by setting the BRGCTL bit in
When configured as a general purpose timer, the SPI BRG interrupt interval is calculated
using the following equation:
The ESPI Data register (see
and the incoming Receive Data register. Reads from the ESPI Data register return the
contents of the Receive Data register. The Receive Data register is updated with the
contents of the shift register at the end of each transfer. Writes to the ESPI Data register
SPI Baud Rate (bps)
registers.
the ESPI Control register to 1.
Table 97. ESPI Rx DMA Descriptor Status field
0
=
P R E L I M I N A R Y
RSS
Table
System Clock Frequency (Hz)
--------------------------------------------------------------------------- -
98) addresses both the outgoing Transmit Data register
=
2 BRG[15:0]
×
System Clock Period (s) BRG[15:0]
ABT
Enhanced Serial Peripheral Interface
ROVR
Product Specification
ZNEO
×
™
Z16F Series
188