NAME

Device::Chip::AVR_HVSP - high-voltage serial programming for AVR chips

DESCRIPTION

This Device::Chip subclass allows interaction with an AVR microcontroller of the ATtiny family in high-voltage serial programming (HVSP) mode. It is particularly useful for configuring fuses or working with a chip with the RSTDISBL fuse programmed, because in such cases a regular ISP programmer cannot be used.

CONNECTIONS

To use this module you will need to make connections to the pins of the ATtiny chip:

ATtiny | tiny84 | tiny85
-------+--------+-------
   SDO |      9 |      7
   SII |      8 |      6
   SDI |      7 |      5
   SCI |      2 |      2
 RESET |      4 |      1
   Vcc |      1 |      8
   GND |     14 |      4

This module recognises the following kinds of adapter and automatically assigns default pin connections for likely configurations:

Bus Pirate | Sparkfun | Seeed    |:| ATtiny
           |  cable   |  cable   |:|
-----------+----------+----------+-+-------
MISO       | brown    | black    |:|    SDO
CS         | red      | white    |:|    SII
MOSI       | orange   | grey     |:|    SDI
CLK        | yellow   | purple   |:|    SCI
AUX        | green    | blue     |:| HV control
+5V        | grey     | orange   |:|    Vcc
GND        | black    | brown    |:|    GND

FTDI |:| ATtiny
-----+-+-------
D0   |:|    SCI
D1   |:|    SDI
D2   |:|    SDO
D3   |:|    SII
D4   |:| HV control

For other kinds of adapter, use the named parameters to the "mount" method to tell the chip driver which ATtiny pin is connected to what GPIO line.

The HV control line from the adapter will need to be able to control a +12V supply to the RESET pin of the ATtiny chip. It should be active-high, and can be achieved by a two-stage NPN-then-PNP transistor arrangement.

Additionally, the SDO pin and the PA0 to PA2 pins of 14-pin devices will need a pull-down to ground of around 100Ohm to 1kOhm.

MOUNT PARAMETERS

sdi, sii, sci, sdo

The names of GPIO lines on the adapter that are connected to the HVSP signal pins of the ATtiny chip.

hv

The name of the GPIO line on the adapter that is connected to the 12V power supply control.

METHODS

The following methods documented in an await expression return Future instances.

start

await $chip->start;

Powers up the device, reads and checks the signature, ensuring it is a recognised chip.

This method leaves the chip powered up with +5V on Vcc and +12V on RESET. Use the power, hv_power or all_power methods to turn these off if it is not required again immediately.

stop

await $chip->stop;

Shut down power to the device.

power

await $chip->power( $on );

Controls +5V to the Vcc pin of the ATtiny chip.

hv_power

await $chip->hv_power( $on );

Controls +12V to the RESET pin of the ATtiny chip.

all_power

await $chip->all_power( $on );

Controls both +5V and +12V supplies at once. The +12V supply is turned on last but off first, ensuring the correct HVSP-RESET sequence is applied to the chip.

$name = $chip->partname

Returns the name of the chip whose signature was detected by the start method.

$memory = $avr->memory_info( $name )

Returns a memory info structure giving details about the named memory for the attached part. The following memory names are recognised:

signature calibration lock lfuse hfuse efuse flash eeprom

(Note that the ATtiny13 has no efuse memory).

The structure will respond to the following methods:

wordsize

Returns number of bits per word. This will be 8 for the byte-oriented memories, but 16 for the main program flash.
pagesize

Returns the number of words per page; the smallest amount that can be written in one go.
words

Returns the total number of words that are available.
can_write

Returns true if the memory type can be written (in general; this does not take into account the lock bits that might futher restrict a particular chip).

%memories = $avr->memory_infos

Returns a key/value list of all the known device memories.

$fuseinfo = $avr->fuseinfo

Returns a Device::Chip::AVR_HVSP::FuseInfo instance containing information on the fuses in the attached device type.

chip_erase

await $avr->chip_erase;

Performs an entire chip erase. This will clear the flash and EEPROM memories, before resetting the lock bits. It does not affect the fuses.

read_signature

$bytes = await $avr->read_signature;

Reads the three device signature bytes and returns them in as a single binary string.

read_calibration

$byte = await $avr->read_calibration;

Reads the calibration byte.

read_lock

$byte = await $avr->read_lock;

Reads the lock byte.

write_lock

await $avr->write_lock( $byte );

Writes the lock byte.

read_fuse_byte

$int = await $avr->read_fuse_byte( $fuse );

Reads one of the fuse bytes lfuse, hfuse, efuse, returning an integer.

write_fuse_byte

await $avr->write_fuse_byte( $fuse, $byte );

Writes one of the fuse bytes lfuse, hfuse, efuse from an integer.

read_lfuse

read_hfuse

read_efuse

$byte = await $avr->read_lfuse;

$byte = await $avr->read_hfuse;

$byte = await $avr->read_efuse;

Convenient shortcuts to reading the low, high and extended fuses directly, returning a byte.

write_lfuse

write_hfuse

write_efuse

await $avr->write_lfuse( $byte );

await $avr->write_hfuse( $byte );

await $avr->write_efuse( $byte );

Convenient shortcuts for writing the low, high and extended fuses directly, from a byte.

read_flash

$bytes = await $avr->read_flash( %args );

Reads a range of the flash memory and returns it as a binary string.

Takes the following optional arguments:

start => INT
stop => INT: Address range to read. If omitted, reads the entire memory.
bytes => INT: Alternative to stop; gives the nubmer of bytes (i.e. not words of flash) to read.

write_flash

await $avr->write_flash( $bytes );

Writes the flash memory from the binary string.

read_eeprom

$bytes = await $avr->read_eeprom( %args );

Reads a range of the EEPROM memory and returns it as a binary string.