GR740-UM-DS, Nov 2017, Version 1.7
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GR740
30.2.4 PLL reconfiguration interface
Three registers allow the PLLs in the design to be reconfigured. One of them is a read-only register
indicating the current configuration, the other two registers are for specifying the new configuration
and commanding the reprogramming.
When the PLL is reprogrammed, the entire system will be reset and the new configuration will be
reflected in the current configuration register. An extra flag field is included in the configuration
which does not fill any function, this can be used by software to preserve a few bits of information
across the restart.
The relation between configuration words and resulting PLL programming is described in section 4.5.
30.2.5 Lockdown register
These different configuration can be locked to prevent further modification using the lockdown regis-
ter. Locking can be revokable or permanent (until next full system reset). Note that the lockdown reg-
ister is not reset when the PLL is reconfigured but only when the external reset signal is asserted.
Table 452.
Groups for pad drive strength control
Group
Description
Pins
0
SDRAM outgoing clock
mem_clk_out
1
SDRAM address/command
mem_wen, mem_rasn, mem_cke[1:0], mem_casn, mem_ba,
mem_addr[12:0]
2
SDRAM chip-select
mem_sn[1:0], mem_addr[14:13]
3
SDRAM data-mask
mem_dqm[11:0]
4
SDRAM data non-muxed
mem_dq[79:64, 41, 32:0]
5
SDRAM data / PCI address /
ETH1
mem_dq[95:80, 63:48, 38]
6
SDRAM data / PCI command
mem_dq[47:43, 40:39, 37:34]
7
SDRAM data / PCI request
mem_dq[42]
8
SDRAM data / PCI inta
mem_dq[33]
9
ETH0
eth0_txer, eth0_txd[7:0], eth0_txen
10
PROMIO control non-muxed
promio_oen, promio_wen, promio_read, prom_cen[0]
11
PROMIO control / CAN
prom_cen[1], io_sn
12
PROMIO address / UART
promio_addr[27:26]
13
PROMIO addr / 1553
promio_addr[25:20]
14
PROMIO addr / UART/SPWD
promio_addr[19:16]
15
PROMIO address non-muxed
promio_addr[15:0]
16
PROMIO data MSB
promio_data[15:8]
17
PROMIO data LSB
promio_data[7:0]
18
GPIO
gpio[15:0]
19
Miscellaneous
dsu_active, proc_errorn, eth0_mdio, eth0_mdc, spi_miso, spi_-
mosi, spi_sck, spi_slvsel[1:0], pll_locked[5:0], wdogn, jtag_tdo,
gr1553_busatxin, gr1553_busbtxin