HT82M99E

Rev. 1.50

21

November 19, 2004

This port configures the input or output mode of Port-B for I/O mode

USB/PS2 Status and Control Register USC (Address 0X1A)

Register Bits

Labels

Read/Write

Option

Functions

USC

(0X1A)

0

PE0

R

SUSPEND

USB suspend mode status bit. When 1, indicates that

the USB system entry is in suspend mode.

1

PE1

W

RMOT_WK USB remote wake-up signal. Default value is 0.

2

PE2

R/W

URST_FLAG USB bus reset event flag. Default value is 0.

3

PE3

R

RESUME_O

When RESUME_OUT EVENT, RESUME_O is set to 1.

Default value is 0.

4

PE4

R

PS2_DAI

USBD-/DATA input

5

PE5

R

PS2_CKI

USBD+/CLK input

6

PE6

W

PS2_DAO

Output for driving USBD-/DATA pin, when working un-

der 3D PS2 mouse function. Default value is 1.

7

PE7

W

PS2_CKO

Output for driving USBD-/DATA pin, when working un-

der 3D PS2 mouse function. Default value is 1.

Endpoint Interrupt Status Register USR (Address 0X1B)

The USR (USB endpoint interrupt status register) register is used to indicate which endpoint is accessed and to select

the serial bus (PS2 or USB). The endpoint request flags (EP0IF, EP1IF) are used to indicate which endpoints are ac-

cessed. If an endpoint is accessed, the related endpoint request flag will be set to

²1² and a USB interrupt will occur (If a

USB interrupt is enabled and the stack is not full). When the active endpoint request flag is served, the endpoint request

flag has to be cleared to

²0².

Register Bits

Labels

Read/Write

Option

Functions

USR

(0X1B)

0

PEC0

R/W

EP0IF

When set to

²1², indicates an endpoint 0 interrupt event.

Must wait for the MCU to process the interrupt event and

clear this bit by firmware. This bit must be

²0², then the

next interrupt event will be processed. Default value is

²0².

1

PEC1

R/W

EP1IF

When set to

²1², indicates an endpoint 1 interrupt event.

Must wait for the MCU to process the interrupt event,

then clear this bit by firmware. This bit must be

²0², then

the next interrupt event will be processed. Default value

is

²0².

2~3 PEC2~PEC3

R/W

¾

Reserved bit, set to

²0²

4

PEC4

R/W

SELPS2

When set to

²1², indicates that the chip is working under

PS2 mode. Default value is

²0².

5

PEC5

R/W

SELUSB

When set to

²1², indicates that the chip is working under

USB mode. Default value is 0.

6

PEC6

R/W

¾

Reserved bit, set to

²0²

7

PEC7

R/W

USB_flag

This flag is used to show that the MCU is in USB mode

(Bit=1). This bit is R/W by FW and will be cleared to zero

after power-on reset. The default is

²0².