Datasheet

104
ATtiny4/5/9/10 [DATASHEET]
8127F–AVR–02/2013
14.7.1 TPIIR – Tiny Programming Interface Identification Register
• Bits 7:0 – TPIIC: Tiny Programming Interface Identification Code
These bits give the identification code for the Tiny Programming Interface. The code can be used be the external
programmer to identify the TPI. The identification code of the Tiny Programming Interface is shown in Table 14-12..
14.7.2 TPIPCR – Tiny Programming Interface Physical Layer Control Register
• Bits 7:3 – Res: Reserved Bits
These bits are reserved and will always read zero.
• Bits 2:0 – GT[2:0]: Guard Time
These bits specify the number of additional IDLE bits that are inserted to the idle time when changing from recep-
tion mode to transmission mode. Additional delays are not inserted when changing from transmission mode to
reception.
The total idle time when changing from reception to transmission mode is Guard Time plus two IDLE bits. Table
14-13 shows the available Guard Time settings.
The default Guard Time is 128 IDLE bits. To speed up the communication, the Guard Time should be set to the
shortest safe value.
Bit 76543210
CSS: 0x0F Programming Interface Identification Code TPIIR
Read/WriteRRRRRRRR
Initial Value00000000
Table 14-12. Identification Code for Tiny Programming Interface
Code Value
Interface Identification
0x80
Bit 76543210
CSS: 0x02
– – – – – GT2 GT1 GT0 TPIPCR
Read/WriteRRRRRR/WR/WR/W
Initial Value00000000
Table 14-13. Guard Time Settings
GT2 GT1 GT0 Guard Time (Number of IDLE bits)
0 0 0 +128 (default value)
001+64
010+32
011+16
100+8
101+4
110+2
111+0