394 The Essential Guide to Serial ATA and SATA Express
optional. A counter identifier value of 000h will indicate the end of the Phy event counter list imple-
mented in the GSCR or PSCR registers. The counter with identifier 000h will have no counter value.
All counter values consume a multiple of 16 bits, with a maximum of 64 bits. Each counter will be
allocated a single register location. The register location will contain both the identifier for the counter
implemented along with the value of the Phy event counter.
Reading Counter Values
Initially, the host may obtain the mapping of counters implemented along with their sizes by submitting
reads starting at GSCR[256] (or PSCR[256]) to obtain the identifiers for the counters on a per port