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Bit in – Rainbow Electronics ATtiny10 User Manual

Page 106

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106

8127B–AVR–08/09

ATtiny4/5/9/10

• 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 reception 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.

14.7.3

TPISR – Tiny Programming Interface Status Register

• Bits 7:2, 0 – Res: Reserved Bits

These bits are reserved and will always read zero.

• Bit 1 – NVMEN: Non-Volatile Memory Programming Enabled

NVM programming is enabled when this bit is set. The external programmer can poll this bit to
verify the interface has been successfully enabled.

NVM programming is disabled by writing this bit to zero.

Table 14-13. Guard Time Settings

GT2

GT1

GT0

Guard Time (Number of IDLE bits)

0

0

0

+128 (default value)

0

0

1

+64

0

1

0

+32

0

1

1

+16

1

0

0

+8

1

0

1

+4

1

1

0

+2

1

1

1

+0

Bit

7

6

5

4

3

2

1

0

CSS: 0x00

NVMEN

TPIPCR

Read/Write

R

R

R

R

R

R

R/W

R

Initial Value

0

0

0

0

0

0

0

0