p87c591vfb NXP Semiconductors, p87c591vfb Datasheet - Page 157

• Manufacturer Part Number: p87c591vfb
• Description: Single-chip 8-bit Microcontroller With Can Controller
• Manufacturer: NXP Semiconductors

Philips Semiconductors
25.1
Oscillator:
Timing symbols (acronyms):
Each timing symbol has five characters. The first character
is always a 't' (= time). the remaining four characters of the
symbol (typed in subscript), depending on their relative
positions, indicate the name of a signal or the logical status
of that signal. the designations are as follows:
Examples:
Table 113 Program security bits for EPROM devices
P = programmed; U = unprogrammed.
Note
1. Any other combination of the security bits is not defined.
2000 Jul 26
LOCK BITS
f
t
A =address
C = clock
D = input data
H = logic level HIGH
I = instruction (program memory contents)
L = Logic level LOW or ALE
P = PSEN
Q = output data
R = RD signal
t = time
V = valid
W = WR signal
X = no longer a valid logic level
Z = float
t
t
Single-chip 8-bit microcontroller with CAN controller
PROGRAM
CLK
CLK
AVLL
LLPL
= clock frequency
= clock period
Timing symbol definitions
= time for ALE LOW to PSEN LOW
= time for address valid to ALE LOW
1
2
3
4
(1)
SB1 SB2 SB3
U
P
P
P
U
U
P
P
U
U
U
P
No Program Security features enabled. (Code verify will still be encrypted by the
Encryption Array if programmed.).
MOVC instructions executed from external Program Memory are disabled from
fetching code bytes from internal memory, EA is sampled and latched on reset,
and further programming of the EPROM is disabled.
Same as 2, also verify is disabled.
Same as 3, and external memory execution is disabled.
157
26 EPROM CHARACTERISTICS
The P8xC591 contains three signature bytes that can be
read and used by an EPROM programming system to
identify the device. The signature bytes identify the device
as an P8xC591 manufactured by Philips:
26.1
If security bits 2 or 3 have not been programmed, the
on-chip program memory can be read out for program
verification.
If the encryption table has been programmed, the data
presented at port 0 will be exclusive NOR of the program
byte with one of the encryption bytes. The user will have to
know the encryption table contents in order to correctly
decode the verification data. The encryption table itself
cannot be read out.
26.2
With none of the security bits programmed the code in the
program memory can be verified. If the encryption table is
programmed, the code will be encrypted when verified.
When only security bit 1 (see Table 113) is programmed,
MOVC instructions executed from external program
memory are disabled from fetching code bytes from the
internal memory. EA is latched on Reset and all further
programming of the EPROM is disabled. When security
bits 1 and 2 are programmed, in addition to the above,
verify mode is disabled.
When all three security bits are programmed, all of the
conditions above apply and all external program memory
execution is disabled.
PROTECTION DESCRIPTION
(030H) = 15H indicates manufactured by Philips
(0031H) = 98H indicates Hamburg
(60H) = 01H indicates P87C591
Program verification
Security bits
Preliminary Specification
P8xC591