Z8F1601 Datasheet, PDF (110/246 Pages) Zilog, Inc. – Z8 Encore Microcontrollers with Flash Memory and 10-Bit A/D Converter

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Table 57. UARTx Baud Rate Low Byte Register (UxBRL)
BITS
7
6
5
4
3
2
1
0
FIELD
BRL
RESET
1
1
1
1
1
1
1
1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/w
ADDR
F47H and F4FH
The UART data rate is calculated using the following equation:
UART Baud Rate (bits/s)
=
----------S---y---s--t--e---m------C-----l-o---c---k-----F----r--e---q---u----e--n----c--y-----(--H----z---)----------
16 × UART Baud Rate Divisor Value
For a given UART data rate, the integer baud rate divisor value is calculated using the fol-
lowing equation:
UART Baud Rate Divisor Value (BRG) = Round_⎝⎛^{S-1---y6---s--}_×^{t--e--U-m----A--C--R---l-To---c---Dk----a-F--t--ra--e---Rq---u-a---et--en----c(--by----i-(t--Hs---/-sz---))}_⎠⎞
The baud rate error relative to the desired baud rate is calculated using the following equa-
tion:
UART Baud Rate Error (%)
=
100
×
⎛
⎝
A-----c--t--u----a---l---D----a---Dt--a--e---sR--i--ra--e-t--de----–_{-D----Da---t-e-a--s--i-R-r---ea--d-t--e--D----a---t--a-----R----a---t--e-⎠⎞}
For reliable communication, the UART baud rate error must never exceed 5 percent.
Table 58 provides information on data rate errors for popular baud rates and commonly
used crystal oscillator frequencies.
PS017610-0404
UART