C541U Datasheet, PDF (40/63 Pages) Siemens Semiconductor Group – 8 BIT CMOS MICROCONTROLLER

C541U
The following table 8 contains the functional description of all C541U-1E pins which are required for
OTP memory programming.
Table 8
Pin Definitions and Functions in Programming Mode
Symbol
RESET
PMSEL0
PMSEL1
Pin Num- I/O*) Function
bers
P-LCC-44
10
I
Reset
This input must be at static “1“ (active) level during the whole
programming mode.
11
I
Programming mode selection pins
13
I
These pins are used to select the different access modes in
programming mode. PMSEL1,0 must satisfy a setup time to the
rising edge of PALE. When the logic level of PMSEL1,0 is changed,
PALE must be at low level.
PMSEL PMSEL Access Mode
1
0
0
0 Reserved
0
1 Read version bytes
1
0 Program/read lock bits
1
1 Program/read OTP memory byte
PSEL
14
PRD
15
PALE
16
XTAL2 20
XTAL1 21
*) I = Input
O = Output
I
Basic programming mode select
This input is used for the basic programming mode selection and
must be switched according figure 10-21.
I
Programming mode read strobe
This input is used for read access control for OTP memory read,
version byte read, and lock bit read operations.
I
Programming mode address latch enable
PALE is used to latch the high address lines. The high address
lines must satisfy a setup and hold time to/from the falling edge of
PALE. PALE must be at low level whenever the logic level of
PMSEL1,0 is changed.
O XTAL2
Output of the inverting oscillator amplifier.
I
XTAL1
Input to the oscillator amplifier.
Semiconductor Group
38