1.15 Input/Output Pullup/Pulldown Currents
Leakage currents may not meet the industry standard specs due
to differently sized weak pullups/pulldowns, during Quasi-
Bidirectional and reset/powerdown modes. Refer to specs for
ILI1 and ILI2 .
1.16 Power-down exit
Pin 37 will not be used to exit power-down mode. Since a digital
clock is supplied, no connection between this Vpp pin and the
power-down circuitry exists.
1.17 Test Mode Entry
Test mode entry will be via four pins: WR, RD, ALE andHLDA
instead of PWM0.
1.18 Power-on Reset
The UT80CRH196KDS will not guarantee the 16-state "pulse
stretching" function of a Reset_n pulse applied at power-up. The
user must hold Reset_n low until the power and clocks stabilize
plus 16-state times, or provide a high to low transition after the
power and clocks have stabilized.
1.19 Pullup/Pulldown states
The INST pin will be driven to a weak low during Reset. The
ALE signal will be driven to a weak high during Bus Hold.
1.20 Modifying the INT_PEND registers
Two operand rd-modify-wr instructions should be used to
modify the INT_PEND registers. Three operand rd-modify-wr
instructions may lose an incoming interrupt.
1.21 Serial Port Synchronous Mode
The last clock rising edge to output float time (TXHQZ) is made
consistent with the output data hold (TXHQX) time of 2 TOSC +/
-50nsec. This is longer than the industry standard of 1 T OSC max.
1.22 Industry Standard Register Indirect with Auto Incre-
ment
The industry standard increments the auto-incremented regis-
ter after determining the external address instead of at the end
of the instruction completion. The UT80CRH196KDS per-
forms the auto-increment function at the end of the instruction
processing. Please reference the example below that shows the
processing difference between the UT80CRH196KDS and the
industry standard:
ST R0, [R0]+
assume R0 holds the value 1000h before the instruction is exe-
cuted.
PROCESSING FLOW FOR THE ST R0, [R0]+
INSTRUCTION
UT80CRH196KDS
Industry Standard
Address = [R0]; 1000h
Address = [R0]; 1000h
R0 ---> Address
R0 = R0+1; 1001h
PROCESSING FLOW FOR THE ST R0, [R0]+
INSTRUCTION
UT80CRH196KDS
Industry Standard
R0 = R0+1; 1001h
R0 ---> Address
* The contents in address * The contents in address
1000h are 1000h
1000h are 1001h
1.23 AC Timing Differences
There are some AC timing differences between the
UT80CRH196KDS and the industry standard 80C196KD.
Most changes resulted in loosened timing specifications. How-
ever, the tRHDZ and tRXDX timing specifications were tight-
ened by 5ns. If you have been designing to the industry
standard timing specifications, it is important to recognize
these two shortened timing specifications.
NOTE: Please visit the UTMC website at www.utmc.com to
obtain the latest data sheet updates, application notes, software
examples, advisories and erratas for the UT80CRH196KDS.
1.24 T2UP-DN Input Signal
Port 2.6 has an alternate function of T2UP-DN enabled by
IOC2.1. The industry standard device appears to allow writes
into Port 2.6 to directly affect the pin state when in the T2UP-
DN mode. (This would allow software control of the T2 direc-
tion, but requires ensuring a one (QBD pullup) is written to
Port 2.6 if the pin is driven externally). The
UT80CRH196KDS device is designed to disable the Port 2.6
output when T2UP-DN is enabled. This protects the P2.6/
T2UP-DN pin from contention with an externally driven sig-
nal, independent of the value written into Port 2.
1.25 NEG 8000h Instruction Operation
The UT80CRH196KDS and the industry standard 80C196KD
set the N-Flag differently when executing the NEG 8000h
instruction. NEG represents the MCS-96 opcode to negate a
defined operand (8000h). When the UT80CRH196KDS exe-
cutes the NEG 8000h instruction, the result becomes 8000h
with both the N-Flag and the V-Flag set. The industry standard
80C196KD, however, executes the NEG 8000h instruction
with a result of 8000h and only the V-Flag set.
1.26 Reserved Opcode EEH
The industry standard 80C196KD using the MCS-96 ISA
declares the opcode EEH as a reserved opcode and does not
guarantee the generation of the Unimplemented Opcode Inter-
rupt. The UT80CRH196KDS, on the other hand, generates the
Unimplemented Opcode Interrupt when the EEH opcode is
executed.
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