CY7C68013
If Autovectoring is enabled (AV2EN = 1 in the INTSETUP register), the FX2 substitutes its INT2VEC byte. Therefore, if the high
byte (“page”) of a jump-table address is preloaded at location 0x0044, the automatically-inserted INT2VEC byte at 0x0045 will
direct the jump to the correct address out of the 27 addresses within the page.
3.8.3
FIFO/GPIF Interrupt (INT4)
Just as the USB Interrupt is shared among 27 individual USB-interrupt sources, the FIFO/GPIF interrupt is shared among 14
individual FIFO/GPIF sources. The FIFO/GPIF Interrupt, like the USB Interrupt, can employ autovectoring.
Table 3-4
shows the
priority and INT4VEC values for the 14 FIFO/GPIF interrupt sources
Table 3-4. Individual FIFO/GPIF Interrupt Sources
Priority
1
2
3
4
5
6
7
8
9
10
11
12
13
14
INT4VEC Value
80
84
88
8C
90
94
98
9C
A0
A4
A8
AC
B0
B4
Source
EP2PF
EP4PF
EP6PF
EP8PF
EP2EF
EP4EF
EP6EF
EP8EF
EP2FF
EP4FF
EP6FF
EP8FF
GPIFDONE
GPIFWF
Notes
Endpoint 2 Programmable Flag
Endpoint 4 Programmable Flag
Endpoint 6 Programmable Flag
Endpoint 8 Programmable Flag
Endpoint 2 Empty Flag
Endpoint 4 Empty Flag
Endpoint 6 Empty Flag
Endpoint 8 Empty Flag
Endpoint 2 Full Flag
Endpoint 4 Full Flag
Endpoint 6 Full Flag
Endpoint 8 Full Flag
GPIF Operation Complete
GPIF Waveform
If Autovectoring is enabled (AV4EN = 1 in the INTSETUP register), the FX2 substitutes its INT4VEC byte. Therefore, if the high
byte (“page”) of a jump-table address is preloaded at location 0x0054, the automatically-inserted INT4VEC byte at 0x0055 will
direct the jump to the correct address out of the 14 addresses within the page. When the ISR occurs, the FX2 pushes the program
counter onto its stack then jumps to address 0x0053, where it expects to find a “jump” instruction to the ISR Interrupt service
routine.
3.9
3.9.1
Reset and Wakeup
Reset Pin
An input pin (RESET#) resets the chip. This pin has hysteresis and is active LOW. The internal PLL stabilizes approximately 200
µs
after V
CC
has reached 3.3V. Typically, an external RC network (R = 100k, C = 0.1
µF)
is used to provide the RESET# signal.
3.9.2
Wakeup Pins
The 8051 puts itself and the rest of the chip into a power-down mode by setting PCON.0 = 1. This stops the oscillator and PLL.
When WAKEUP is asserted by external logic, the oscillator restarts and after the PLL stabilizes, and the 8051 receives a wakeup
interrupt. This applies whether or not FX2 is connected to the USB.
The FX2 exits the power down (USB suspend) state using one of the following methods:
• USB bus signals resume
• External logic asserts the WAKEUP pin
• External logic asserts the PA3/WU2 pin.
The second wakeup pin, WU2, can also be configured as a general purpose I/O pin. This allows a simple external R-C network
to be used as a periodic wakeup source.
3.10
3.10.1
Program/Data RAM
Size
The FX2 has eight kbytes of internal program/data RAM, where PSEN#/RD# signals are internally ORed to allow the 8051 to
access it as both program and data memory. No USB control registers appear in this space.
Document #: 38-08012 Rev. *C
Page 11 of 52
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