Z8F6421PM020SC Datasheet, PDF (129/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
109
(BRG[15:0]) that sets the data transmission rate (baud rate) of the UART. The UART data
rate is calculated using the following equation:
UART Data Rate (bits/s) = _{1----6----×}--S---Uy---s-A-t--e-R--m---T---C--B---l-ao---uc---k-d----F-R---r-a-e--t-q-e--u--D--e--ni--v--c-i-y-s--o--(-r-H---V-z---)-a---l-u----e-
When the UART is disabled, the Baud Rate Generator can function as a basic 16-bit timer
with interrupt on time-out. To configure the Baud Rate Generator as a timer with interrupt
on time-out, complete the following procedure:
1. Disable the UART by clearing the REN and TEN bits in the UART Control 0 register
to 0.
2. Load the desired 16-bit count value into the UART Baud Rate High and Low Byte
registers.
3. Enable the Baud Rate Generator timer function and associated interrupt by setting the
BRGCTL bit in the UART Control 1 register to 1.
When configured as a general purpose timer, the interrupt interval is calculated using the
following equation:
Interrupt Interval (s) = System Clock Period (s) ×BRG[15:0] ]
UART Control Register Definitions
The UART control registers support the UART and the associated Infrared Encoder/
Decoders. For more information on the infrared operation, refer to the Infrared Encoder/
Decoder chapter on page 120.
UART Transmit Data Register
Data bytes written to the UART Transmit Data register (Table 51) are shifted out on the
TXDx pin. The Write-only UART Transmit Data register shares a Register File address
with the Read-only UART Receive Data register.
Table 51. UART Transmit Data Register (UxTXD)
BITS
7
6
5
4
3
2
1
0
FIELD
TXD
RESET
X
R/W
W
ADDR
F40H and F48H
PS019915-1005
UART