Programming Data Transfer Length and Usage of Exponent

Zynq UltraScale+ Device Technical Reference Manual (UG1085)

Document ID
UG1085
Release Date
2022-09-15
Revision
2.3 English

This section describes some examples on programming different data transfer lengths. Only the length related fields are mentioned.

When 128 bytes are read/written from the SPI flash, the generic FIFO configuration uses the values in Table: Generic FIFO Configuration for 128 Bytes.

Table 24-16:      Generic FIFO Configuration for 128 Bytes

Description

immediate_data

data_xfer

exponent

128 bytes

8'h80

1'b1

1'b0

When 1,000 bytes are read/written from the SPI flash, the generic FIFO configuration uses the values described by the options listed in Table: Generic FIFO Configuration for 1,000 Bytes.

Table 24-17:      Generic FIFO Configuration for 1,000 Bytes

 

Description

immediate_data

data_xfer

exponent

Option 1

512 bytes using exponent

8'h09

1'b1

1'b1

256 bytes

8'h08

1'b1

1'b1

Remaining 232 bytes

8'hE8

1'b1

1'b0

Option 2

256 bytes

8'h08

1'b1

1'b1

256 bytes

8'h08

1'b1

1'b1

256 bytes

8'h08

1'b1

1'b1

Remaining 232 bytes

8'hE8

1'b1

1'b0

When 1G bytes are read/written from the SPI flash, the generic FIFO configuration uses the values in Table: Generic FIFO Configuration for 1G Bytes.

Table 24-18:      Generic FIFO Configuration for 1G Bytes

Description

immediate_data

data_xfer

exponent

1G bytes

8'h1E

1'b1

1'b1

When 64 bytes are read/written from the SPI flash, the generic FIFO configuration uses the values in Table: Generic FIFO Configuration for 64 Bytes.

Table 24-19:      Generic FIFO Configuration for 64 Bytes

Description

immediate_data

data_xfer

exponent

64 bytes

8'h40

1'b1

1'b0