CY7C65113-SXC Cypress Semiconductor Corp, CY7C65113-SXC Datasheet - Page 25

• Manufacturer Part Number: CY7C65113-SXC
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C65113-SXC

• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Package Type: SOIC
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

Document #: 38-08002 Rev. *D
During a reset, the contents of the Global Interrupt Enable Register and USB End Point Interrupt Enable Register are cleared,
effectively disabling all interrupts,
The interrupt controller contains a separate flip-flop for each interrupt. See Figure 14-3 for the logic block diagram of the interrupt
controller. When an interrupt is generated, it is first registered as a pending interrupt. It stays pending until it is serviced or a reset
occurs. A pending interrupt only generates an interrupt request if it is enabled by the corresponding bit in the interrupt enable
registers. The highest priority interrupt request is serviced following the completion of the currently executing instruction.
When servicing an interrupt, the hardware does the following:
The instruction in the interrupt table is typically a JMP instruction to the address of the Interrupt Service Routine (ISR). The user
can reenable interrupts in the interrupt service routine by executing an EI instruction. Interrupts can be nested to a level limited
only by the available stack space.
The Program Counter value as well as the Carry and Zero flags (CF, ZF) are stored onto the Program Stack by the automatic
CALL instruction generated as part of the interrupt acknowledge process. The user firmware is responsible for ensuring that the
processor state is preserved and restored during an interrupt. The PUSH A instruction should typically be used as the first
command in the ISR to save the accumulator value and the POP A instruction should be used to restore the accumulator value
just before the RETI instruction. The program counters CF and ZF are restored and interrupts are enabled when the RETI
instruction is executed.
The IDI and EI instruction can be used to disable and enable interrupts, respectively. These instruction affect only the Global
Interrupt Enable bit of the CPU. If desired, EI can be used to re-enable interrupts while inside an ISR, instead of waiting for the
RETI that exits the ISR. While the global interrupt enable bit is cleared, the presence of a pending interrupt can be detected by
examining the IRQ Sense bit (Bit 7 in the Processor Status and Control Register).
14.1
The Interrupt Vectors supported by the USB Controller are listed in Table 14-1. The lowest-numbered interrupt (USB Bus Reset
interrupt) has the highest priority, and the highest-numbered interrupt (I
1. Disables all interrupts by clearing the Global Interrupt Enable bit in the CPU (the state of this bit can be read at Bit 2 of the
2. Clears the flip-flop of the current interrupt.
3. Generates an automatic CALL instruction to the ROM address associated with the interrupt being serviced (i.e., the Interrupt
Processor Status and Control Register, Figure 13-1).
Vector, see Section 14.1).
AddrA ENP2 Int
USB Reset Int
Interrupt Vectors
I
2
C Int
1
1
1
CLK
D
D
CLK
CLK
D
CLR
CLR
CLR
Q
Q
Q
(Reg 0x21)
Enable [2]
(Reg 0x20)
(Reg 0x20)
Enable [6]
Enable [0]
Figure 14-3. Interrupt Controller Function Diagram
USB Reset IRQ
AddrA EP0 IRQ
AddrA EP1 CLR
AddrA EP1 IRQ
AddrA EP2 CLR
AddrA EP2 IRQ
AddrB EP0 IRQ
AddrB EP1 IRQ
DAC IRQ
128-µs CLR
128-µs IRQ
1-ms CLR
1-ms IRQ
AddrA EP0 CLR
AddrB EP0 CLR
AddrB EP1 CLR
Hub CLR
Hub IRQ
DAC CLR
GPIO CLR
GPIO IRQ
I
USB Reset Clear Interrupt
I
2
Interrupt Priority Encoder
2
C CLR
C IRQ
2
C interrupt) has the lowest priority.
IRQout
Vector
Acknowledge
To CPU
CPU
Interrupt
Interrupt
Enable
Global
CLR
Bit
CY7C65113C
Controlled by DI, EI, and
RETI Instructions
IRQ Sense
Page 25 of 49
Int Enable
Sense
IRQ