PCA84C922AP PHILIPS [NXP Semiconductors], PCA84C922AP Datasheet - Page 24

• Manufacturer Part Number: PCA84C922AP
• Description: Microcontrollers for universal infrared remote transmitter applications
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
13 EMULATION
The PCA84C923D can be used as the emulation chip for
both the PCA84C92X and PCA84CX22 ranges of
microcontrollers. The emulation system is shown in Fig.19.
A 64 kbyte EPROM (27C256) is used as the Coding Table
and stores all data code. The EPROM should be removed
when members of the PCA84CX22 range are being
emulated.
The PCA84C923D has two additional outputs: INTO and
RSTO which are used for emulation purposes only. The
INTO output is the result of the AND operation carried out
internally on the T0/INT and Port 1 inputs; this is shown in
Fig.1. The RSTO output is the result of the OR operation
carried out internally on the RESET input and the
Watchdog Timer reset; this is also shown in Fig.1. The
INTO and RSTO pins of the PCA84C923D are connected
to the T0/INT and RESET pins of the bond-out chip,
respectively.
The RESET and T0/INT inputs are connected to the
corresponding pins of the PCA84C923D (in other 84CXXX
emulation systems they are connected to the
corresponding pins of the PCF84C00).
1997 Oct 22
Microcontrollers for universal infrared
remote transmitter applications
24
In the emulation mode, port lines P10 to P13 of the
PCA84C923D are used as the inputs for derivative control
signals DXWR, DXRD, DXALE and EXDIN. Therefore,
port lines P20 to P23 (which are ANDed internally to
emulate the wake-up function of port lines P10 to P13) are
connected to port lines P10 to P13 of the bond-out chip.
If port lines P14 to P17 of the PCA84C923D have been
masked for the wake-up function, then they must not be
connected to the corresponding pins of the bond-out chip.
However, these sets of pins can be connected if the
wake-up option has not been selected.
When the PCA84C923D is used as the emulation chip all
ports should have the mask option 1S. After a
Power-on-reset the only data that can be written to
Derivative Port 5 is FFH.
When the PCF84C00 is used for emulation purposes its
ports should have the mask option 1S. However, as some
ports may be used as scan lines (for example Port 1 and
Port 6) they will have mask options of 1R or 3R. In this
case, after a Power-on-reset, these ports should have 00H
written to them.
PCA84C922; PCA84C923
Product specification