ST10F273Z4 STMicroelectronics, ST10F273Z4 Datasheet - Page 156

• Manufacturer Part Number: ST10F273Z4
• Description: 16-BIT MICROCONTROLLER WITH MAC UNIT, UP TO 832 KBYTES FLASH MEMORY AND UP TO 68 KBYTES RAM
• Manufacturer: STMicroelectronics

Specifications of ST10F273Z4

• Single Voltage Supply: 5 V ±10%

Electrical characteristics
Note:
24.8.14
24.8.15
Note:
156/188
Figure 47. External clock drive XTAL1
When Direct Drive is selected, an external clock source can be used to drive XTAL1. The
maximum frequency of the external clock source depends on the duty cycle: when 64 MHz
is used, 50% duty cycle shall be granted (low phase = high phase = 7.8ns); when for
instance 32 MHz is used, a 25% duty cycle can be accepted (minimum phase, high or low,
again equal to 7.8ns).
Memory cycle variables
The tables below use three variables which are derived from the BUSCONx registers and
represent the special characteristics of the programmed memory cycle. The following table
describes, how these variables are to be computed.
External memory bus timing
In next sections the external memory bus timings are reported. The given values are
computed for a maximum CPU clock of 40 MHz.
It is evident that when higher CPU clock frequency is used (up to 64 MHz), some numbers in
the timing formulas become zero or negative, that in most of the cases is not acceptable or
not meaningful at all. In these cases, it is necessary to relax the speed of the bus setting
properly t
All external memory bus timings and SSC timings reported in the following tables are
granted by design characterization and not fully tested in production.
ALE extension
Memory cycle time wait states
Memory tri-state time
A
, t
Description
C
and t
F
.
t1
VIH2
Symbol
t
t
t
C
A
F
t2
t3
TCL x [ALECTL]
2TCL x (15 - [MCTC])
2TCL x (1 - [MTTC])
tOSC
VIL2
Values
t4
ST10F273Z4