ZLF645E0P2832G Zilog, ZLF645E0P2832G Datasheet - Page 95

• Manufacturer Part Number: ZLF645E0P2832G
• Description: Microcontrollers (MCU) 32K Flash 1K RAM 28 pin
• Manufacturer: Zilog

Specifications of ZLF645E0P2832G

• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 32 KB
• Data Ram Size: 1 KB
• Interface Type: ICP, UART
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 24
• Number Of Timers: 3
• Maximum Operating Temperature: + 70 C
• Mounting Style: Through Hole
• Package / Case: PDIP-28
• Minimum Operating Temperature: 0 C
• Lead Free Status / Rohs Status: Details

PS026407-0408
Note:
UART Baud Rate Generator
Baud Rate Generator Interrupts
If the BRG interrupt enable is set, the UART Receiver interrupt asserts when the UART
Baud Rate Generator reloads. This action allows the BRG to function as an additional
counter if the UART functionality is not employed.
The UART Baud Rate Generator creates a lower frequency baud rate clock for data
transmission. The input to the Baud Rate Generator is the system clock. The UART Baud
Rate Constant register contains an 8-bit baud rate divisor value (BCNST[7:0]) that sets the
data transmission rate (baud rate) of the UART. For programmed register values other than
00h
When the UART Baud Rate Low register is programmed to
calculated as follows:
When the UART Baud Rate Generator is used as a general-purpose counter, the counters
time-out period can be computed as follows based upon the counters clock input being a
divide by 16 of the system clock and the maximum count value being 255:
The relationship between the XTAL1 clock frequency and the system clock frequency must
be considered before making this computation and is dependent upon the programming of
bit 2 of User Option Byte 1 as well as the programming of bit 0 of the SMR register.
Depending on the programmed values, the system clock frequency can be a divide by 1, a
divide by 2, or a divide by 16 of the XTAL1 clock.
When the UART is disabled, the BRG can function as a basic 8-bit timer with interrupt on
time-out.
UART Data Rate (bps)
UART Data Rate (bps)
Time-Out Period (us)
, the UART data rate is calculated using the below equation:
=
=
=
16 x UART Baud Rate Divisor Value (BCNST)
16 x UART Baud Rate Divisor Value (BCNST)
System Clock Frequency (Hz)
System Clock Frequency (MHz)
System Clock Frequency (Hz)
4096
ZLF645 Series Flash MCUs
00h
Product Specification
, the UART data rate is
Operation
87