8XC152JA JB JC JD
EPSEN is used in conjunction with Port 5 and Port 6
program memory operations EPSEN functions like
PSEN during program memory operation but sup-
ports Port 5 and Port 6 EPSEN is the read strobe to
external program memory for Port 5 and Port 6
EPSEN is activated twice during each machine cycle
unless an external data memory operation occurs on
Port(s) 0 and Port 2 When external data memory is
accessed the second activation of EPSEN is
skipped which is the same as when using PSEN
Note that data memory fetches cannot be made
through Ports 5 and 6
When EBEN is high and EA is low all program mem-
ory operations take place via Ports 5 and 6 The high
byte of the address goes out on Port 6 and the low
byte is output on Port 5 ALE is still used to latch the
address on Port 5 Next the op code is read on Port
5 The timing is the same as when using Ports 0 and
2 for external program memory operations
80C152JB JD General Description
The 80C152JB JD is a ROMless extension of the
80C152 Universal Communication controller The
80C152JB has the same five 8-bit I O ports of the
80C152 plus an additional two 8-bit I O ports Port 5
and Port 6 The 80C152JB JD also has two addi-
tional control pins EBEN (EPROM
Bus ENable)
and
EPSEN (EPROM bus
Program Store ENable)
EBEN selects the functionality of Port 5 and Port 6
When EBEN is low these ports are strictly I O simi-
lar to Port 4 The SFR location for Port 5 is 91H and
Port 6 is 0A1H This means Port 5 and Port 6 are not
bit addressable With EBEN low all program memo-
ry fetches take place via Port 0 and Port 2 (The
80C152 is a ROMless only product) When EBEN is
high Port 5 and Port 6 form an address data bus
called the E-Bus (EPROM-Bus) for program memory
operations
Table 1 Program Memory Fetches
EBEN
0
0
1
1
EA
0
1
0
1
Program
Fetch via
P0 P2
N A
P5 P6
P5 P6
P0 P2
PSEN
Active
N A
Inactive
Inactive
Active
EPSEN
Inactive
N A
Active
Active
Inactive
Comments
Addresses 0 – 0FFFFH
Invalid Combination
Addresses 0– 0FFFFH
Addresses 0– 1FFFH
Addresses
t
2000H
Table 2 8XC152 Product Differences
ROMless
Version
80C152JA
80C152JB
80C152JC
80C152JD
NOTES
e
options available
0 standard frequency range 3 5 MHz to 12 MHz
0 ‘‘
b
1’’ frequency range 3 5 MHz to 16 5 MHz
CSMA CD
and
HDLC SDLC
HDLC SDLC
Only
ROM
Version
Available
(83C152JA)
PLCC
and
DIP
PLCC
Only
5I O
Ports
7I 0
Ports
(83C152JC)
4
INTEL [ INTEL CORPORATION ]
