CY7C67300_13 Datasheet, PDF (17/112 Pages) Cypress Semiconductor – EZ-Host™ Programmable Embedded USB Host and Peripheral Controller with Automotive AEC Grade Support

CY7C67300
Registers
Some registers have different functions for a read vs. a write
access or USB host vs. USB device mode. Therefore, registers
of this type have multiple definitions for the same address.
The default register values listed in this data sheet may be
altered to some other value during the BIOS initialization. Refer
to the BIOS documentation for register initialization information.
Processor Control Registers
There are nine registers dedicated to general processor control.
Each of these registers are covered in this section and are
summarized in Table 21.
Table 21. Processor Control Registers
Register Name
CPU Flags Register
Register Bank Register
Hardware Revision Register
CPU Speed Register
Power Control Register
Interrupt Enable Register
Breakpoint Register
USB Diagnostic Register
Memory Diagnostic Register
Address
0xC000
0xC002
0xC004
0xC008
0xC00A
0xC00E
0xC014
0xC03C
0xC03E
R/W
R
R/W
R
R/W
R/W
R/W
R/W
W
W
CPU Flags Register [0xC000] [R]
Table 22. CPU Flags Register
Bit #
15
14
13
12
11
10
9
8
Field
Reserved...
Read/Write
-
-
-
-
-
-
-
-
Default
0
0
0
0
0
0
0
0
Bit #
Field
Read/Write
Default
7
6
5
...Reserved
-
-
-
0
0
0
4
Global
Interrupt
Enable
R
X
3
Negative
Flag
R
X
2
Overflow
Flag
R
X
1
Carry
Flag
R
X
0
Zero
Flag
R
X
Register Description
The CPU Flags register is a read only register that gives
processor flags status.
Global Interrupt Enable (Bit 4)
The Global Interrupt Enable bit indicates if the Global Interrupts
are enabled.
1: Enabled
0: Disabled
Negative Flag (Bit 3)
The Negative Flag bit indicates if an arithmetic operation results
in a negative answer.
1: MS result bit is ‘1’
0: MS result bit is not ‘1’
Overflow Flag (Bit 2)
The Overflow Flag bit indicates if an overflow condition occurred.
An overflow condition can occur if an arithmetic result was either
larger than the destination operand size (for addition) or smaller
than the destination operand must allow for subtraction.
1: Overflow occurred
0: Overflow did not occur
Carry Flag (Bit 1)
The Carry Flag bit indicates if an arithmetic operation resulted in
a Carry for addition, or Borrow for subtraction.
1: Carry/Borrow occurred
0: Carry/Borrow did not occur
Zero Flag (Bit 0)
The Zero Flag bit indicates if an instruction execution resulted in
a ‘0’.
1: Zero occurred
0: Zero did not occur
Document Number: 38-08015 Rev. *L
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