Z8F6421PM020SC Datasheet, PDF (252/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
232
Figure 57 and Table 120 provide timing information for UART pins for the case where the
Clear To Send input signal (CTS) is not used for flow control. In this example, it is
assumed that the Driver Enable polarity has been configured to be Active Low and is rep-
resented here by DE. DE asserts after the UART Transmit Data Register has been written.
DE remains asserted for multiple characters as long as the Transmit Data register is writ-
ten with the next character before the current character has completed.
DE
(Output)
TXD
(Output)
T₁
Start Bit 0 Bit 1
T₂
Bit 7 Parity ^Stop
End of
Stop Bit(s)
Figure 57. UART Timing without CTS
Table 120. UART Timing without CTS
Delay (ns)
Parameter Abbreviation
Minimum
Maximum
T₁
DE Assertion to TXD Falling Edge (Start) Delay 1 Bit period 1 Bit period +
1 * XIN period
T₂
End of Stop Bit(s) to DE Deassertion Delay
1 * XIN period 2 * XIN period
PS019915-1005
Electrical Characteristics