From NAS-Central Buffalo - The Linkstation Wiki

Contents

Contents 1 Contents 2 Functions 2.1 Overview of Functions 3 UART Communication with Main CPU 3.1 Transmission System 3.1.1 UART Basic Settings 3.2 Communication with Main CPU 3.3 Protocol 3.3.1 Preamble 3.3.2 Main CPU -> Microcomputer 3.3.2.1 Data Payload 0 Bytes 3.3.2.2 Data Payload n bytes 3.3.3 Microcomputer -> Main CPU 3.4 ACK/NACK List 3.4.1 Write Command 3.4.2 Read Command 3.4.3 Interrupt + Read Command 3.5 Command 3.5.1 Command Construction 3.5.1.1 Write (CPU -> Microcomputer) 3.5.1.2 Read (Microcomputer -> CPU) 3.5.2 Commands with no data payload 3.5.3 Data Payload 1 Byte Command 3.5.4 Data Payload 2 Byte Command 3.6 Buzzer ON/OFF 3.6.1 Command 3.6.2 Data 3.7 Buzzer pitch 3.7.1 Command 3.7.2 Data 0 3.7.3 Data 1 3.7.4 Relationship between sound pitch and frequency 3.8 System Watchdog 3.8.1 Command 3.8.2 Data 3.9 Temperature Read 3.9.1 Command 3.9.2 Data 3.10 SW Read 3.10.1 Command 3.10.2 Data 3.11 LED Display 3.11.1 Command 3.11.2 Data 3.11.3 Data Meaning 3.12 LED brightness 3.12.1 Command 3.12.2 Data 3.12.3 Data Meaning 3.13 HDD Power control 3.13.1 Command 3.13.2 Data 4 ACK/NACK List

Functions

Overview of Functions

Communicates with the main CPU via UART. The main functions are shown below.

• Power SW monitoring
• Initialization SW monitoring
• Power control
• Temperature measurement
• Buzzer control
• Watchdog function (However, watchdog function is disabled on u-boot)
• LAN ACT monitoring
• LED display
• Reset sequence generation
• LED Illumination

UART Communication with Main CPU

Transmission System

UART Basic Settings

• Transmission speed: 38400bps
• Data bit: 8bit
• Parity: Even
• Stop bit: 1 bit or more

Communication with Main CPU

• Basic communication is performed by the transmission of commands, data, and parity.
• When switches etc are pressed, a level interrupt occurs. The interrupt is cleared when reporting to the CPU is completed.
• If many frame errors occur, regulate the guard time on the main CPU.

Protocol

Preamble

The receive buffer is completely cleared by sending FF 35 times.

Main CPU -> Microcomputer

Data Payload 0 Bytes

1	Transfer direction (BIT7)	Data payload (0)
2	Command
3	Parity 0-(byte1+byte2)

Data Payload n bytes

1	Transfer direction (BIT7)	Data payload ()
2	Command
3	Data 0
	• • • •
n-1	Data n
n	Parity 0 - Σ(byte 1 to byte n-1)

Microcomputer -> Main CPU

Responses to commands other than the read command (when data does not exist)

1	0 (BIT7)	Data payload (1)
2	Sent command
3	ACK
4	Parity 0-(byte1+byte2+byte3)

Response to read command

1	0 (BIT7)	Data payload (N)
2	Sent command
3	Data 1
n-1	Data N
n	Parity 0 - Σ(byte 1 to byte n-1)

Response when communication error occurs

1	0 (BIT7)	Data payload (1)
2	Sent command
3	NACK
4	Parity 0-(byte1+byte2+byte3)

ACK/NACK List

HEX	mnemonic
0x00	ACK	Good
0xF1	OVER_RUN	UART physical layer error Physical layer buffer over
0xF2	FRAMING_ERR	UART physical layer error Physical layer frame error
0xF3	PARITYERROR	UART physical layer error Physical layer parity error
0xF4	Invalid_COM	Command does not exist
0xF5	Com_len_err	Command and data payload values do not correspond
0xF6	RX_BUFF_OVER	Payload larger than 32 bytes specified.
0xF7	DATA_PARITY_ERROR	Data parity is wrong.

Write Command

LED Lighting control etc Command Micro- computer CPU DATA0 DATA1 DATAn(MAX31) PARITY Switch to data transfer phase Switch to command phase Command (OPCODE) ACK Command Command 2nd byte PARITY

Read Command

Temperature read by CPU DATA0 DATA1 DATAn(MAX31) PARITY Command (OPCODE) PARITY Command CPU Micro- computer Switch to data transfer phase Switch to command phase

Interrupt + Read Command

SW Micro- computer DATA0 DATA1 DATAn(MAX31) PARITY Interrupt assert Interrupt negate Switch to data transfer phase Switch to command phase Command (OPCODE) PARITY Command CPU

Command

Command Construction

The command is a 2 byte command.

Write (CPU -> Microcomputer)

bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
0	0	Length

bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
OPCODE

Read (Microcomputer -> CPU)

bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
1	0

bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
OPCODE

Command List

Commands with no data payload

Command		Command name	Microcomputer operation
1Byte	2Byte
FF	---	NOP	Used in preamble
0x00	0x02	BOOT_START	Boot starts, CPU sends this command at the start. If this command is not received within 10 seconds after reset, power does not go on. This is displayed during boot.
0x00	0x03	BOOT_END	The boot display is completed, and the device operates normally. If this command is not received within 5 minutes, power goes off.
0x00	0x06	POFF	Power switches off.
0x00	0x0C	SHUT_DOWN_WAIT	SHUT DOWN preparations
0x00	0x0D	SHUT_DOWN_WAIT_N	Cancel SHUT DOWN preparations
0x00	0x0E	REBOOT	REBOOT (system reset) start

Data Payload 1 Byte Command

Command		Command name	Microcomputer operation
1Byte	2Byte
0x01	0x30	BZ_ON	Buzzer sounds.Buzzer control, with fine selection of whether to sound for 1 byte of data
--------
0x01	0x33	FANSPEED_CTL	FAN speed can be selected.0 Stopped 3 Maximum Settings above 3 (only enabled for lower 2 bits)
0x80
0x01	0x35	SYSTEM_WDT	Performs clear and settings for system watchdog.
0x80
	0x37	TEMP	Obtains the temperature.Receivable data is in Centigrade
0x80
	0x38	FANSPEED	Obtains fan speed informationDouble the number of FAN revolutions in 3 seconds is displayed. rpm= (obtained data) ×10.
0x80
0x01	0x3a	LED_BRIGHT	Adjusts the brightness of the current LED
0x80
0x01	0x3b	HDD_POWER	Controls the HDD power supply
0x80
	0x3c	MAIN_STATUS	Obtains the STATUS of the microcomputer
0x80

Data Payload 2 Byte Command

Command		Command name	Microcomputer operation
1Byte	2Byte
0x02	0x50	LED_CPU_MCON	Switches LED between main CPU controland microcomputer control.
0x80
0x02	0x51	LED_ON_OFF	Controls whether the LED is on or off
0x80
0x02	0x52	LED_BLINK	Selects the LED for LED flashing display
0x80
0x02	0x53	BZ_FREQ	Buzzer frequency settings
0x80
0x02	0x54	LED_PATTERN	Controls LED flashing
0x80

Buzzer ON/OFF

Command

0×01	First operand read 0×80
0×30	Second operand

Data

0×00	Stop the sound
0×01	[Pi-po]
0×02	[Pi]
0×03	Continuous sound [Piiiii-]
0×04	Sounds every 0.3 seconds
0×10	Repeats sounding for 0.5 seconds then stopping for 0.3 seconds.
0×20	[Pi-po-pa-po]

Buzzer pitch

Command

0×02 First operand setting 0×80 First operand reading of settings. 0×53 Second operand

Data 0

Frequency settings lower order

Data 1

Frequency settings upper order

Relationship between sound pitch and frequency

A A# B C C#D D# E F F# G G# 55 58 62 65 69 73 78 82 87 92 98 104 110 117 123 131 139 147 156 165 175 185 196 208 220 233 247 262 277 294 311 330 349 370 392 415 440 466 494 523 554 587 622 659 698 740 784 831 880 932 988104711091175124513191397148015681661 176018651976209322172349248926372794296031363322 Relationship between values set on microcomputer and sound pitch A A# B C C#D D# E F F# G G# FC04F062 E273 D60AC852 BE8CB399 A9D69F70 963D 8E0B858C7F08 7746 7068 6A4A6429 5EB25949 5475 4FB8 4B1E 4705 430F 3F42 3BA33868 3525 323D2F59 2CC52A3A27DC25A6 2382 2187 1FA1 1DE01C34 1A9E191E17B5 1662 151D13EE12CD 11C1 10C3 0FD00EEC0E16 0D4C0C8C0BD80B2F0A8E09F7 0968 08E0 0860 07E8 0777 070C06A6 0647 05EC0597 0547 04FB04B4 3F4 1FA FD

System Watchdog

Command

0×01 First operand read 0×80 when setting 0×35 Second operand

Data

Set the time until the power goes OFF for forced OFF. You can set up to 255 seconds. However, setting to 0 will cause the system watchdog to stop and not operate. If read is performed, the time for the watchdog to operate is displayed. 0×FF – (time to shutdown) = Setting value

Temperature Read

Command

0×80 First Operand (read only) 0×37 Second operand

Data

The temperature on the board can be read. The read data is signed char. The data is from -55°C to 125°C.

SW Read

Command

0x80 First Operand (read only) 0×36 Second operand

Data

bit7-bit4 bit4 bit3 bit2 bit1 Bit0 0 1 F_INIT_SW 1 1 Power SW KURO BOX/PRO Microcomputer Communication Specifications Rev.1.0 14/16 If SW or INITSW is pressed, an interrupt occurs. You can research the cause of an interrupt by reading the SW. Reading this resistor clears the interrupt.

• If the SW is released at the point when read is started, the value returns to 1. Therefore,

measure the pressed time on the CPU to judge. bit4: Always 1 bit3: 0 when INIT_SW is pressed bit2: Always 1 bit1: Always 1 bit0: Power_SW 0 when Power_SW is pressed

LED Display

Command

0x01 First operand read 0x80 when setting Second operand Switching LED control rights: 0×50 Switching LED on/off: 0×51 Flash LED: 0×52

Data

DATA0 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 0 0 0 0 LINK DIAG INFO Power DATA1 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 0 0 0 0 0 0 0 0

Data Meaning

Control Rights Switching • 0: LED control performed by microcomputer • 1: LED control performed by CPU Switching on/off • 0: Switch LED off • 1: Light LED Flash Switching • 0: Do not flash LED • 1: Flash LED

LED brightness

Command

0×00 First operand 0×80 read 0X3a Second operand

Data

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 LED Illumination

Data Meaning

LED Illumination Setting possible in the 0-0xf range 0×0= Off 0×f = Maximum illumination

HDD Power control

Command

0×00 First operand 0×80 (read) 0X3b Second operand

Data

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 0 0 HDD

ACK/NACK List

HEX mnemonic 0x00 ACK Good 0xF1 OVER_RUN UART physical layer error Physical layer buffer over 0xF2 FRAMING_ERR UART physical layer error Physical layer frame error 0xF3 PARITYERROR UART physical layer error Physical layer parity error 0xF4 Invalid_COM Command does not exist 0xF5 Com_len_err Command and data payload values do not correspond 0xF6 RX_BUFF_OVER Payload larger than 32 bytes specified. 0xF7 DATA_PARITY_ERROR Data parity is wrong.