PC87591L datasheet(281/437 Pages) NSC

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5.0 Host Controller Interface Modules (Continued)

Revision 1.07

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Status Register (STATUS, Legacy 6416)

This register provides the status of the host interface keyboard channel buffers (DBBIN and DBBOUT) and the value of mes-

sages sent by the core using the Status bits to the host. The Status register can also be read by the core as HIKMST. The

Status register is cleared (0016) on reset.

Location: As defined in LDN 0616 registers, index 6216 and 6316

Type: R

Data In Buffer Register (DBBIN, Legacy 6016)

This register allows the host to write to DBBIN register while setting Status register bit IBF and clearing Status register bit

A2 bit. If the core interrupt on IBF is enabled (IBFCIE in HICTRL register is set to 1), writing to this register asserts it (high).

Location: As defined in LDN 0616 registers, index 6016 and 6116

Type: W

Command In Buffer Register (COMAND, Legacy 6416)

This register allows the host to write to DBBIN register while setting IBF and A2 bits in the Status register. If the core interrupt

on IBF is enabled (IBFCIE in HICTRL register is set to 1), writing to Data In Buffer asserts it (high).

Location: As defined in LDN 0616 registers, index 6216 and 6316

Type: W

Bit

76543210

Name

ST3-ST0

IBF

OBF

Reset

00000000

Bit

Description

OBF (Output Buffer Full). The bit is set when the keyboard/mouse channel’s DBBOUT is written to the core

(i.e., writing to HIKDO or HIMDO registers). The bit is cleared by a host processor read from the

keyboard/mouse channel output buffer (6016).

IBF (Input Buffer Full). The bit is set when the keyboard/mouse channel’s DBBIN is written to the host

processor (i.e., writing to either address 6016, data or address 6416, control). The bit is cleared when the core

reads the input buffer (HIKMDI).

F0 (Flag 0). A general-purpose flag that can be set or cleared by the core firmware.

A2 (A2 Address). Holds the value of the A2 signal in the last write operation of the host to the keyboard/mouse

channel’s input buffer (i.e., A2=0 for Data In Buffer write and A2=1 for Command In Buffer write).

7-4

ST3-ST0 (Status). Four general-purpose flags that can be set or cleared by the core firmware.

Bit

76543210

Name

Keyboard/Mouse DBBIN Data

Bit

Description

7-0

Keyboard/Mouse DBBIN Data.

Bit

76543210

Name

Keyboard/Mouse DBBIN Data

Bit

Description

7-0

Keyboard/Mouse DBBIN Data.

PC87591L Datasheet(PDF) 281 Page - National Semiconductor (TI)

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