Attaching SDRAM to the STM32F469AG
Refer to the STM32F469 Reference Manual, Section 12.7 on page 357.
The maximum SDRAM size supported on each of the STM32's SDRAM banks is 256MB, organized internally as 13 Rows, 11 Columns, 4 Banks, and with a 32-bit data bus.
Your proposed IS42S32160 has 13 Rows, 9 Columns, 4 banks and a 32-bit bus - so there should be no trouble using it.
You could use a 1Gb memory chip (since 1Gb == 128MB), but you'd need to ensure that the rows, columns &amp; internal banks don't exceed what the STM32 can handle.
You're likely to find many 1Gb ICs which have 8 internal banks (with fewer rows or columns), which would lead to only part of the memory being accessible).
If you're prepared to do some manual bank-swapping you might be able to connect an 8-bank memory IC's BA2 pin to a gpio on your micro.
Or alternatively possibly use some external logic with both of the micro's CS outputs to both select the memory MEMCS = !(!CS0 || !CS1) and drive BA2 BA2 = CS0 &amp;&amp; !CS1. Of course this method means you can't use 2 8-bank memories as you're using both CS outputs to drive one IC.
Considering actual part availability of large SDR SDRAMs supported by the STM32 micro, probably the best way to max out the external ram would be to connect multiple 8- or 16-bit SDRAMs in parallel to the STM's 32-bit data bus.
For example:

a pair of EM63B165TS 512Mbx16-bit on CS0 and another pair on CS1 for a total of 2Gbit over 4 devices
4 IS42S86400F 512Mbitx8-bit on CS0 and another 4 on CS1 for a total of 4Gbit over 8 devices.